Ingredient:

• 1 tablespoon olive oil
• 1 medium onion, thinly sliced
• 3 tablespoons mayonnaise
• 2 tablespoons prepared horseradish
• 1 package (12 ounces) Hawaiian sweet rolls
• 1 pound shredded cooked roast beef
• 6 slices cheddar or mozzarella cheese
• 3 tablespoons butter, melted
• 1 tablespoon everything seasoning blend