Guinness Beer

Ingredients : 2 tablespoons olive oil 1 onion chopped 3 cloves garlic minced 1 teaspoon salt ½ teaspoon ground black pepper 2 pounds beef stew meat cubed 3 cups stout beer (such as Guinness®) 2 potatoes peeled and sliced 2 potatoes peeled and quartered salt and ground black pepper to...