Slice the onion thinly.

Heat butter in a frying pan over medium heat, add onion, and sauté until softened. Add shrimp and cook until they change color.

Add flour to the pan and stir until no raw flour remains. Gradually add milk and consomme, stirring until thickened. Season with salt and pepper.

In a bowl, mix warm rice with butter and salt and pepper until the butter melts (Butter Rice).

Layer butter rice, white sauce, and pizza cheese in a heatproof dish. Bake in a toaster oven for about 5 minutes until the surface is golden brown.