Squeeze the chorizo meat out of their casings and into a 12-inch sauté pan. Place the pan over medium heat and use a wooden spatula to break the chorizo into small pieces. Sauté until it's cooked through, about 5 minutes. Remove the chorizo from the pan and set it aside in a medium-sized mixing bowl.

Keeping the heat at medium, add the onion and garlic to the pan and cook until the onions are soft, about 4 minutes. Then add the rosemary and cook for another 30 seconds or so, until it's very aromatic.

Add the tomatoes and chipotles into the onion mixture. Stir to combine and cook only to heat the tomatoes. Add this to the bowl with the chorizo and set aside.

If the pan doesn't have much grease left from the chorizo, coat the bottom with olive oil, and turn the heat to medium-high. Add the potatoes, brown them on all sides, and cook just until they're tender, about 10 minutes.

While the potatoes are cooking, use a whisk to whip the eggs until they are completely blended, and season them with salt and pepper.

Carefully pour the chorizo mixture into the pan with the potatoes and season to taste with salt and pepper. With the heat at medium-low, add the whipped eggs to the pan. Use a small spoon or fork to move the ingredients around a bit, to ensure that egg seeps all the way to the bottom of the pan. Cook for approximately 2 minutes, sprinkle the top surface with the cheese, cover, and turn the heat to low. Cook covered for approximately 8 more minutes and remove the lid. The frittata is done when all of the egg has solidified and puffed up a bit.

Gently slide the frittata out of the sauté pan onto a plate or cutting board. Cut the frittata into about 12 even wedges.