Preheat your oven to 350°F (175°C).
Roast the poblano peppers over an open flame until charred; place in a bowl and cover for 10 minutes.
In a skillet, cook the chopped onion and garlic until translucent.
Add ground meat to the skillet and cook until browned.
Stir in cooked rice, diced tomatoes, cumin, chili powder, salt, and pepper.
Remove skins from the roasted peppers and slice them open to remove seeds.
In a baking dish, layer half of the meat mixture, followed by half of the cheese.
Place the poblano peppers on top and fill them with the remaining meat mixture.
Top with the remaining cheese and sour cream.
Bake in the preheated oven for 30-40 minutes until bubbly and golden.