Wash and slice the mushrooms, shrimp, and onion into bite-sized pieces.
Beat the eggs well and set aside.
Add oatmeal and water or broth to a pot and bring to a boil.
When the oatmeal softens, add the mushrooms, shrimp, and onion and continue to cook.
Once the ingredients are cooked, pour in the beaten eggs and gently stir until cooked through.
Season with salt and pepper to taste.