1. Preheat your oven to 400°F (200°C) and line a baking sheet with parchment paper.
2. In a skillet over medium heat, cook the ground beef or turkey until browned, seasoning with garlic powder, Italian seasoning, salt, and pepper. Remove from heat and drain any excess grease.
3. Place the English muffin halves on the prepared baking sheet, cut-side up. Spread about 1–2 tablespoons of marinara sauce on each half.
4. Top each muffin with a few slices of bell pepper, followed by a spoonful of the cooked meat.
5. Generously sprinkle shredded mozzarella cheese over the toppings.
6. Bake in the oven for 8–10 minutes, or until the cheese is melted and bubbly with golden edges.
7. Remove from the oven, garnish with fresh basil or parsley if desired, and serve warm.