The Tiniest Loco Moco Ever!

Name: Tiny Loco Moco
Yield: 0
Ingredients: 1 tablespoon ground beef; Salt and pepper; 1 teaspoon vegetable oil; 1/2 teaspoon minced sweet onion; 1 teaspoon chopped mushroom; 1/2 tablespoon beef broth; 1/4 teaspoon cornstarch; 1 tablespoon cooked rice; Fried egg; Parsley, to garnish