Pizza-Style Mozzarella Quinoa With Roasted Tomatoes

Heat the oven to 400F. On a baking sheet, toss the tomatoes with 1/2 tablespoon of olive oil. Spread the tomatoes in one layer and sprinkle with the oregano; add salt and pepper to taste. Roast until the tomatoes are soft and blistered, about 30 minutes. Increase the oven temperature to broil.
While the tomatoes are roasting, prepare the quinoa per the package directions in an oven-safe medium saucepan. Remove from the heat, add the mozzarella, and stir well to combine. Add salt and pepper to taste.
In a nonstick skillet over medium-high heat, add 1/2 tablespoon of olive oil and heat until hot but not smoking. Add the bell pepper and onion and cook until tender, about 10 minutes. Remove to a plate and keep warm.
Add the remaining 1/2 tablespoon olive oil to the skillet and heat until hot but not smoking. Add the mushrooms and cook until golden, 3 to 5 minutes. Remove to a plate and keep warm.
Top the quinoa evenly with the roasted tomatoes and mozzarella. Broil until the mozzarella is melting and browning in spots, about 3 to 5 minutes. Divide the quinoa evenly among four bowls and top with the peppers and onions, mushrooms, fresh basil, and a sprinkle of red pepper flakes (if using).