Vegetarian Sushi Bake with Mushrooms

This vegetarian Sushi Bake is unique and absolutely delicious. Bringing together elements of sushi and the comfort of a casserole, this easy sushi bake is a really fun appetizer or main course, and it's always a big hit.

I’m all about creative and comforting recipes for casual entertaining, and that is exactly what this Vegetarian Sushi Bake is. Not to mention scrumptious!

When I've seen anything reminiscent of this on a menu, it's often called Dynamite Sushi Bake.

Disclaimer: I’m not an expert in Japanese or other Asian cuisines, nor is this an authentic Japanese dish. I’m am however an expert in making delicious food. 😉

What is a Sushi Bake?

• A Sushi Bake is not close to traditional sushi, and is not an authentic Japanese dish.
• The Sushi Bake was created, interestingly enough, by a celebrity nail artist from the Philippines. Her name is Mimi Qui Reyes and she introduced it in 2015, calling it The Original Baked California Roll. Here's her story.
• I’m sharing a Vegetarian Sushi Bake made with mushrooms, though there are many sushi bake variations. Some are made with shrimp and salmon, and they're most often made with crab and sometimes include cream cheese. It's likened to a deconstructed California roll.
• A Sushi Bake casserole is almost always eaten with small sheets of Nori (dried roasted seaweed), and is finished with a drizzle of a sauce made of Sriracha and mayonnaise (called Spicy Mayo), and slices of avocado.

The Ingredients

(I often suggest brands I love and use — these are only suggestions and this is not a sponsored post.)

• sushi rice - I use Calrose rice which is grown in California and is easy to find in most most grocery stores. Calrose is a Japanese-style medium grain rice, and it’s excellent in this recipe.
• Unseasoned rice vinegar - Made from fermented rice, this adds a subtly sweet and tart flavor to the rice.
• sugar
• salt - I use Kosher salt which has a larger flake size and usually doesn't contain additives. If you use table salt, use half the amount.
• Furikake - Fruikake is a popular Japanese seasoning (or condiment) that is typically made of seaweed and toasted sesame seeds. It can be found in Asian grocery stores and upscale markets like Whole Foods and Erewhon (if you’re in S. California), and more and more it’s showing up in larger main stream grocery stores. You can also get it here online.
• neutral oil - Grapeseed or vegetable.
• Button or Crimini mushrooms - Choose mushrooms whose caps are domed and curled under, as this is a sign of freshness. The caps should appear dry and smooth.
• Shiitake mushrooms - Look for shiitakes with the thickest caps you can find, and avoid those that look wet, slimy, or shriveled.
• soy sauce or Tamari - I recommend low-sodium.
• Chili paste -  I use Sambal Oelek which you can get at just about any grocery store. The touch of heat is delicious with the sweetness in the rice.
• Nori - Nori is dried edible seaweed with a sweet and salty flavor. For the Sushi Bake we’re using snack-sized Nori Sheets which you can find in almost any large grocery store.
• Avocado - The avocado is a quintessential topping for this Sushi Bake. The creamy texture and mellow flavor balances all of the other flavors. Ripe avocados will feel lightly soft but it will not feel “mushy” to the touch.
• green onions (scallions) - This adds just the right amount of crunch to each bite.
• Mayonnaise - I like mayonnaise made with avocado oil. This one is great.
• Sriracha - You can find this hot sauce pretty much anywhere.

(See recipe card below for quantities.)

Substitutions and Variations

• Rice vinegar. Rice vinegar can be substituted with white vinegar and lemon juice. Use 2 tablespoons of the vinegar and 1 tablespoon lemon juice.
• Chili Paste and Sriracha. While not exactly the same, you can substitute either one for the other. Other Sriracha substitutions include a mix of ketchup and tobasco or Tapatio sauce. All of these will vary in heat, so you should add them the same way we season to taste. Here’s how.
• Furikake. To substitute Furikake, mix toasted sesame seeds with Nori (1:1). Crumble the Nori until it’s in tiny pieces before mixing.
• Shiitake mushrooms. Oyster mushrooms can replace the Shiitakes.
• I like the mix of the mushroom varieties, though you can use more or less of either one, or all of one or the other.
• If you love the flavor of sesame, and want more it than the Furikake offers, add about a tablespoon of sesame oil to the mushrooms.
• Vegan? If you’re vegan, or serving vegan guests, use a vegan mayonnaise for the sauce, or purée avocado with the Sriracha. You can also use the Sriracha without the mayo, which will just be spicier. (And be sure to check the ingredient list on the Furikake to be sure it’s vegan, as some contain bonito flakes (katsuobushi in Japanese).

Recipe Tips

• To save time, use Seasoned rice vinegar, which is often called Sushi vinegar, and already contains sugar and salt. Your Vegetarian Sushi Bake will still be delicious.
• When rinsing the raw rice, it’s helpful to stir it with your hands as the water runs over it. You’ll notice the water go from slightly opaque to clear as you do this.
• Cover the cooked rice with a damp paper or kitchen towel so it stays moist.
• While a rice paddle is the ideal tool for combining the sushi vinegar with the rice, a flat-edged wooden spatula will also work well.
• If you’d like less heat, use less (or omit) chili paste from the mushroom mixture.

How to Make a Vegetarian Sushi Bake

- Make sushi vinegar. In a small sauce pan, combine the vinegar, sugar and salt, Place it over low-medium heat and whisk just until the sugar and salt have dissolved. Set aside.

- Make sipcy mayo. Mix the mayonnaise with the Sriracha in a small dish and set aside.

- Rinse the measured rice in a fine mesh strainer until the water runs clear. Add the rice to a medium-sized pot with the water. Do not turn the heat on and let it soak for 15 minutes.

- After it's soaked, bring it to a boil, cover and turn the heat to the lowest setting. Cook for 15 minutes, or until all of the water has been absorbed.

- While the rice is still hot, add it into a large non-reactive bowl (like wood or stainless steel), and immediately pour in the sushi vinegar mixture and the Furikake. Use a rice paddle to gently “cut” the rice to incorporate it. Do not stir because the rice will become mushy.

Set the rice aside with a damp towel over it.

- Generously coat the bottom of a large skillet (ideally 12 to 14-inch) with the oil, and place it over high medium-heat. Add half of the mushrooms and, stirring often, sauté until they have shrunk considerably, when there’s clear space in the pan. Add the remaining mushrooms and again, stirring often, sauté until they're all soft and there’s no liquid in the pan.

- Deglaze the pan with the soy sauce. Mix it into the mushrooms and use a flat-bottomed spatula to scrape off any bits that are stuck to the bottom. Then add the chili paste and season lightly with salt.  

- Spread the rice evenly into a 9 x 13-inch baking dish, and then add the mushroom mixture on top. Bake in a preheated 375℉ oven for about 20 minutes, or until the top is golden.

- When you’re ready to serve, add about 1 ½ tablespoons of the Sushi Bake to the center of each Nori sheet, and gently fold the sides around it. Top with an avocado slice and chopped scallions.

- Immediately place them on a serving platter or individual plates, drizzle with the Sriracha sauce and serve.

Pro Tip: Since the rice is sticky, the best way to add the Sushi Bake to the Nori is to use a cookie scoop. (A 1 ½-inch scoop is perfect.)

Serving Suggestions

• Ideally when the Sushi Bake is served, it's warm to hot, and the other ingredients are room temperature.
• I usually serve this with all of the components on the table in separate dishes— the casserole, Nori sheets, avocado slices, chopped onions and sauce. This way they can be assembled by each person as they’re eating them. This is the best way to keep the Nori crisp, and it can be fun. Otherwise, assemble as close to serving time as possible.  
• Whether you serve vegetarian Sushi Bake as a main course or as an appetizer, it’s delicious with light and refreshing salads and sides, fish and tofu. Below are a few delicious ideas:

• Spicy Asian Slaw
• Pickled Broccoli
• Spicy Pickled Cucumbers
• Sriracha-Honey Glazed Tofu
• Miso-Garlic Ginger Tofu
• Baby Boy Choy with Crispy Garlic

Can you make it ahead?

The sushi casserole and sauce portions of a vegetarian sushi bake can be made ahead of time. The sauce up to four days ahead. The casserole is at its best right after it's made, but it's still very good if it's made a day or two ahead and reheated. Both should be stored in air tight containers or wrapped tightly in the refrigerator.

If they’re not be assembled at the table, you should assemble it with the Nori, avocado, onions and the sauce when you’re ready to serve.

How to Reheat the Sushi Bake

If you’ve made the casserole portion ahead, reheat it in a 375℉ oven, covered, just until it’s warmed through, about 15 minutes.

You can also reheat it in the microwave if it’s in a microwave-safe dish. (It can be uncovered.)

More Asian-Style Comfort Food Recipes

• Gai Lan Egg Soup
• Shirataki Noodle Stir-Fry
• Vegetarian Pad Thai with Peanut Sauce
• Bok Choy Shiitake Mushroom Gratin

Vegetarian Sushi Bake FAQs

* Even if you know an ingredient is vegan or gluten-free, you should still always read the ingredient labels, as on occasion they might not be. *

I hope you love this recipe as much as I do!