In a skillet, heat 1 tablespoon of olive oil over medium heat. Add the sliced onions and a pinch of salt. Cook, stirring occasionally, until the onions are soft and golden brown, about 15-20 minutes.

In another skillet, heat the remaining tablespoon of olive oil over medium-high heat. Add the minced beef, garlic powder, Worcestershire sauce, salt, and pepper. Cook until browned and fully cooked, about 10-15 minutes.

Toast the bread slices lightly. Layer the cooked minced beef on the bottom slice, top with caramelized onions, and add cheese if desired. Place the top slice of bread on and press down gently.

Cut the sandwich in half and serve immediately with your choice of sides.