Hamburger Steak with Mushroom Onion Gravy

Hamburger Steak with Mushroom Onion Gravy

8 ounces mushrooms, cleaned and sliced
1 medium onion, peeled and halved and sliced into half moons
4 tablespoons butter, divided
1 tablespoon olive oil
12 ounces ground sirloin
1 14.5 ounce can low sodium beef broth
1 teaspoon beef base
3 tablespoons & 2 teaspoons flour
salt and pepper, to taste

In a large saute pan, melt 1 tablespoon of butter over medium-high heat and saute' the mushrooms and onions until the onions are wilted and the mushrooms have browned. Season lightly with salt and pepper and remove to a small bowl.
Form two oval shaped burgers with the ground sirloin and season lightly with salt and pepper. In the same pan, add the 1 tablespoon of olive oil and cook the burgers, turning once, until they are medium. Remove to a plate and cover to keep warm.
Add the remaining butter and heat until the butter sizzles. Add the flour and cook for one minute. Slowly add the beef broth and the beef base, and cook and stir until thickened and bubbly. Stir in the mushrooms and onions and heat through.
To serve, place a sirloin burger on a plate and top with some of the gravy.