Cook the base. Prepare quinoa, farro, brown rice, or whole-wheat pasta according to package directions.
Fluff or drain and set aside.
Prep the chicken. Pat chicken dry and slice breasts horizontally into cutlets, about 1/2-inch thick. Season both sides with 1 teaspoon salt, 1/2 teaspoon black pepper, 1 teaspoon garlic powder, 1/2 teaspoon onion powder, and 1 teaspoon Italian seasoning.
Set up dredging. In one shallow bowl, beat the egg. In another, mix panko with 2 tablespoons Parmesan and a pinch of salt and pepper.
Coat lightly. Dip each cutlet in egg, let excess drip, then press one side into the panko mixture. Only coat one side to keep it lighter while still giving a crispy top.
Toast the crumbs. Heat 1–2 tablespoons olive oil in a large skillet over medium heat.
Place chicken crumb-side down and cook until golden and crisp, 3–4 minutes. Flip and cook another 2–3 minutes, until the chicken is just cooked through (165°F/74°C).
Warm the sauce. In a small pot, heat marinara over low with a pinch of chili flakes if you like heat. Taste and adjust salt.
Sauté the greens. In the same skillet, add a splash of oil if needed.
Toss in spinach with a pinch of salt and cook 1–2 minutes, just until wilted. Squeeze a little lemon over the greens for brightness.
Melt the cheese. Turn the heat low. Spoon a little warm marinara over each chicken piece, sprinkle mozzarella and remaining Parmesan, cover, and let it melt for 1–2 minutes.
Alternatively, broil on a sheet pan for 1–2 minutes until bubbly.
Assemble the bowls. Divide the base among 4 bowls. Top with sautéed greens, cherry tomatoes, and a piece of cheesy chicken. Spoon extra marinara around the bowl, not over the crispy side, so it stays crunchy.
Finish and serve. Drizzle with a touch of olive oil, scatter torn basil or parsley, and add fresh black pepper.
Serve hot.