Preheat oven. Preheat the oven to 425°F, and adjust a couple of racks towards the center.
Mix the bok choy coating. In a small bowl, combine the oil, chili paste, garlic and ginger. Mix until it's evenly blended and set aside.
Prepare the bok choy. Cut the root ends off of each bok choy -- the leaves will separate when you do this. Wash and dry them. Coat both sides of each leaf individually with the oil mixture. You can do this with a pastry brush, your hands, or by gently dredging each leaf through it. As you do this, lay them in a single layer on a baking sheet (you will need approximately 2). Then sprinkle them lightly with sea salt.
Roast the bok choy. Place the baking sheets in the preheated 425°F oven and roast them until they are starting to become crisp, about 6 minutes. Gently flip each one over and bake just until they are even more crisp -- similar to a actual chip, but a bit softer and more fragile. This should take about 2 more minutes.
Cool, garnish and serve. To cool the chips, place them in a single layer on a baking rack and let them sit for at least 5 minutes -- and if they seem particularly oily, place them on paper towels to cool. Sprinkle with dried chili flakes and serve.