For the sauce:

Peel shallots and garlic and cut into fine cubes. Quarter the mushrooms.

Sauté the garlic and shallots in the butter for about 5 minutes over medium heat. Turn up the heat and add the mushrooms, fry for about 20 minutes until the resulting liquid has almost evaporated. Deglaze with beer and beef stock and add salt, sugar and balsamic vinegar.

Preserve until mushrooms and liquid have reached the same level. Mix the starch with a little cold water, stir in and bring to the boil briefly until the sauce has thickened. Then remove from the heat and set aside.

Steak Medium Rare Grilling:

Take the steak out of the fridge early to bring it to room temperature. Heat the Otto Grill up on a big flame for 3 minutes. Salt the steak and grill on Meat-O-Meter level 4 for 1 minute, then turn and grill again for 1 minute. Then turn the grill down to a low flame and cook the steak on Meat-O-Meter level 5 for 2 minutes, turn and cook for another 2 minutes. Turn off the grill and let the steak cook for 5 minutes.

Then cut open and serve with the beer sauce.