- 1 lemon, zested, juiced
- 1/2 shallot, finely chopped
- 1 pound grape tomatoes, halved
- 2 tablespoons extra-virgin olive oil
- 1 tablespoon Sherry vinegar
- 1 teaspoon kosher salt
- 1 teaspoon freshly ground black pepper
- 1 teaspoon Worcestershire sauce
- 1/4 teaspoon cayenne pepper
- 5 tablespoons finely grated fresh horseradish, divided
- 2 celery stalks, thinly sliced
- 3 tablespoons coarsely chopped celery leaves
- 6 tablespoons mayonnaise
- 6 slices toasted rye bread
- Combine lemon zest, lemon juice, shallot, tomatoes, oil, vinegar, salt, black pepper, Worcestershire sauce, cayenne, and 1 Tbsp. horseradish in a large bowl. Let marinate 10 minutes, then stir in celery stalks and leaves.
- Meanwhile, combine mayonnaise and remaining 4 Tbsp. horseradish in a small bowl. Spread 1 Tbsp. horseradish-mayonnaise on each slice of rye. Top toasts evenly with tomato mixture.