Prepare Caramelized Onions:
Heat oil in skillet over medium-high heat, until smoking; add onions. Turn heat to medium and stir frequently until onions are completely caramelized, chestnut brown and practically falling apart tender.
Reduce the vegetable or chicken stock in medium saucepan to 1/4 cup. Stir onions into reduced stock; cook until lightly glazed. Season with balsamic vinegar, salt and pepper.
Prepare TABASCO® Horseradish Sauce:
Whip cream lightly in a small bowl. Mix red wine vinegar, mayonnaise, TABASCO® Sauce and mustard in a separate bowl. Fold horseradish into cream; mix with Dijon mixture. Add salt and pepper to taste.
Cook hamburgers until desired doneness. Serve burger on a toasted slider bun; top with caramelized onions and TABASCO® Horseradish Sauce.
Created by Chef Laurent Tourondel