Preheat your oven to 350 degrees f. and line a large baking try with parchment paper.
Heat oil in a medium nonstick skillet over medium heat. Add ground beef and cook, stirring and breaking the meat with a spatula until nicely browned.
Drain any excess fat, then return the skillet to the heat.
Sprinkle browned beef with all seasonings and continue to cook until nicely combined.
Stir in diced tomatoes and simmer over medium for about 4-5 minutes, then remove from heat.
Meanwhile, prepare your peppers; Using a small knife, remove the seeds and membranes, then layer them on the prepared baking tray as shown.
Fill each with some of your meat mixture, then top with shredded cheese if desired.
Bake in your preheated oven for 8-10 minutes, or until cheese is melted, and everything is heated through.
Remove from oven and top with desired toppings.
