1?½ cups frozen grilled corn (such as Trader Joe’s®)
½ cup chopped fresh cilantro
salt and ground black pepper to taste
2 cups shredded Colby Jack cheese
¾ cup spicy green salsa
or more to taste
1 tablespoon tomato paste
¾ cup hot water
Place black beans in a multi-functional pressure cooker. Add enough water to cover by a few inches. Close and lock the lid. Select high pressure according to manufacturer’s instructions; set timer for 20 minutes. Allow 10 to 15 minutes for pressure to build.
Release pressure using the natural-release method according to manufacturer’s instructions, about 10 minutes. Unlock and remove lid. Drain black beans and rinse out the pot.
Combine 4 cups water and quinoa in the pressure cooker pot. Close and lock the lid. Select Brown Rice function and set timer for 8 minutes. Allow 5 to 10 minutes for pressure to build.
Release pressure carefully using the quick-release method according to manufacturer’s instructions, about 5 minutes. Unlock and remove lid. Remove pot carefully using oven mitts, fluff quinoa with a fork, and let cool.
Preheat the oven to 375 degrees F (190 degrees C).
Heat oil in a large skillet over medium heat. Add onion, red bell pepper, garlic, and cumin; cook and stir until softened and fragrant, about 5 minutes. Stir in corn until heated through, 3 to 5 minutes. Remove from heat and stir in 1/4 cup cilantro. Season with salt and pepper.
Stir black beans, onion mixture, 1 cup Colby Jack cheese, and green salsa into the pot of quinoa. Spread mixture in a large baking dish.
Dissolve tomato paste in 3/4 cup hot water. Drizzle over the quinoa mixture. Sprinkle remaining Colby Jack cheese evenly over the top.
Bake in the preheated oven until cheese is melted, about 25 minutes. Garnish with remaining cilantro and scallions.