In a small bowl mix the brown sugar, garlic and beer.
Place the steaks in a resealable plastic bag and add the marinade.
Place it in the refrigerator for 2 to 4 hours.
Preheat the grill to medium heat.
Once the steak is marinated take it out of the refrigerator and set aside so the meat can rise to room temperature, about 5 to 10 minutes.
Remove steaks from plastic bag and dry steaks off with paper towels.
Brush with oil season with salt and freshly ground black pepper and place on grill. Cook for 5 minutes on each side for medium rare. Once cooked let it rest for 10 minutes.
Place on serving plates.
In a medium skillet, add butter, onions and mushrooms.
Saute until golden brown, about 5 minutes.
Place into bowl and set aside. In the same skillet add 2 tablespoons of oil. Crack the eggs over the skillet and fry. Once ready place mushrooms, onions and eggs on top of the steaks and serve.