2 bell peppers, each cut into 8 pieces
2 cloves garlic, thinly sliced
2 tablespoons olive oil
kosher salt and black pepper
1 small onion, chopped
1 pound ground beef chuck
1 cup frozen corn
2 teaspoons ground ancho chili powder or standard chili powder
8 corn tortillas, warmed
cut-up avocado, grated Cheddar, salsa, fresh cilantro, and lime wedges, for serving