Mushroom-and-Swiss Sliders with Spicy Fry Sauce

INGREDIENTS

• 1/3 cup Mayonnaise
• 2 Tablespoons Ketchup
• 1 teaspoon Cayenne Pepper (less If You're Sensitive To Spice!)
• 4 Tablespoons Butter
• 1/2 whole Medium Onion, Finely Diced
• 8 ounces, weight White Mushrooms, Chopped Finely
• 1/2 cup White Or Red Wine (optional)
• 4 dashes Worcestershire Sauce
• Kosher Salt And Freshly Ground Black Pepper
• 2 pounds Ground Beef
• 4 Tablespoons Heavy Whipping Cream
• 1 teaspoon Kosher Salt
• Freshly Ground Black Pepper
• 4 slices Swiss Cheese, Cut Into Four Squares
• 8 whole Dinner (or Slider) Rolls, Split