French Onion Sliders Recipe | Say Mmm

Ingredients

• 2 sweet onions
• 3 tablespoons butter
• 2 pounds ground beef
• 2 tablespoons beef base
• 1 teaspoon onion powder
• 1/2 teaspoon celery seed
• 1/2 teaspoon dried parsley
• 1/4 teaspoon ground black pepper
• 2 tablespoons butter
• 8 ounces Grand Cru cheese, grated or very thinly sliced
• 12 toasted slider buns or hard rolls, split in half