Heat oven to 375°F.
Line a 15 x 10-inch baking pan with aluminum foil.
Cut bell peppers in half lengthwise; remove seeds and membranes; Combine the rice, corn, black beans, cilantro, lime juice, chili powder and cumin in a bowl.
Gently stir in 3/4 cup fontina.
Season with salt and pepper to taste.
Spoon filling into bell peppers.
Place on prepared pan.
Sprinkle each with remaining fontina.
Bake for 12-15 minutes or until filling is heated through.
Serve immediately.