
Start by pouring the beer into 6 cups with the cubed beef, dividing it among them.
Transfer them to a large skillet over medium to low heat with boiling water.
Cover it and let everything cook for 15 minutes.
In a large bowl, add the diced tomatoes, the grated mozzarella cheese, the mushrooms cut into smaller pieces and the mayonnaise.
Season with the salt, the black pepper and mix.
In a large baking tray, add the onions cut into strips and the potatoes cut into slices.
Season with salt and black pepper to taste.
Add the mixture we prepared and spread it evenly.
Next, add the cooked beef.
Season with salt and black pepper to taste.
Sprinkle the grated mozzarella cheese all over the top.
Place in a preheated oven at 180° C (350° F) and bake for 40 minutes.
Serve.