Reverse Sandwich

Name: Reverse Sandwich
Yield: Yields 1 sandwich
Ingredients: Salt and pepper, to taste; 1 portobello mushroom; Olive oil, as needed; Salt and pepper, to taste; 2 oz. butter; 6 oz. filet mignon, trimmed and cut into two half-inch patties; 2 oz. horseradish sauce; 2 slices white bread, cut with a 4 inch diameter ring mold; 2 slices cheddar cheese (or preferred cheese); 2 slices cheddar cheese (or preferred cheese); 3 slices Roma tomato (or 1 slice of a large Heirloom or Jersey tomato); 3 arugula leaves (or substitute Bibb or peppercress); 3 slices Roma tomato (or 1 slice of a large Heirloom or Jersey tomato); 3 slices Roma tomato (or 1 slice of a large Heirloom or Jersey tomato); 1 cup sour cream; 2 thin slices red onion; ¼ cup chives, chopped fine; ¼ cup fresh grated horseradish; 1 Tbsp. cracked black pepper