Mushroom-and-Swiss Sliders with Spicy Fry Sauce

Name: Mushroom-and-Swiss Sliders with Spicy Fry Sauce
Prep time: 15 min
Cook time: 30 min
Total time: 45 min
Cuisine: European, American
Ingredients: 1/3 c. Mayonnaise; 2 tbsp. Ketchup; 1 tsp. Cayenne Pepper (less If You're Sensitive To Spice!); 4 tbsp. Butter; 1/2 whole Medium Onion, Finely Diced; 8 oz. weight White Mushrooms, Chopped Finely; 1/2 c. White Or Red Wine (optional); 4 dashes Worcestershire Sauce; Kosher Salt And Freshly Ground Black Pepper; 2 lb. Ground Beef; 4 tbsp. Heavy Whipping Cream; 1 tsp. Kosher Salt; Freshly Ground Black Pepper; 4 slices Swiss Cheese, Cut Into Four Squares; 8 whole Dinner (or Slider) Rolls, Split