1. In a small bowl, combine the horseradish, Worcestershire sauce and mayonnaise. Season to taste with salt and pepper.
(This can be made in advance and stored in the refrigerator for up to 3 days.)
2. Preheat the grill to medium-high.
3. Shape the ground sirloin into 4 patties, about 1/2-inch thick. Season the patties with salt and pepper.
4. Grill the patties on both sides until the burgers are just cooked through, about 5 minutes per side.
5. Toast the onion rolls on the grill.
6. Serve the burgers with sliced red onion and horseradish sauce on the toasted onion rolls.
Serving Size: 1 burger

Number of Servings: 4
| Per Serving |
| Calories |
363 |
Carbohydrate |
34 g |
| Fat |
10 g |
Fiber |
2 g |
| Protein |
32 g |
Saturated Fat |
4 g |
| Sodium |
691 mg |
|
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