01 -
Place a stick of butter in an 11 x 13-inch casserole dish.
02 -
Put the dish in an oven preheated to 350°F (175°C), and allow the butter to melt.
03 -
Once melted, carefully remove the dish from the oven. Add the rice, French onion soup, beef consomme, and sliced mushrooms to the dish, allowing them to pool atop the melted butter.
04 -
Gently stir with a fork or spoon, ensuring the rice is well dispersed throughout the liquid.
05 -
Place the dish back in the oven and bake for 30 to 40 minutes, or until the top is golden and inviting.