Best Ever Russian Beef Stroganoff

Ingredients (12)

• + 1 ½ tablespoons all-purpose flour add to pantry
• + ¾ teaspoon salt add to pantry
• + ⅛ teaspoon ground black pepper add to pantry
• + 1 pound beef sirloin, cut into 1/4-inch wide strips add to pantry
• ✓ 3 tablespoons butter
• + 1 cup thinly sliced mushrooms add to pantry
• + ½ cup chopped onion add to pantry
• ✓ 1 clove garlic, minced, or more to taste
• + 1 tablespoon tomato paste add to pantry
• + 1 ¼ cups cold beef stock add to pantry
• ✓ 1 cup sour cream
• + 3 tablespoons cooking sherry add to pantry