Use whatever rice you have on hand—leftover rice actually works best here, since it holds together well in the filling. No grill? These bake beautifully at 400°F for 25 to 30 minutes, until the peppers are tender and the cheese is golden. To make them heartier, stir in browned sausage or ground beef and a handful of chopped greens. Leftovers keep in the fridge for up to 3 days and reheat well in the oven or air fryer.