Step 1Combine the shrimp, fennel, mayonnaise, red onion, dill, capers and red pepper flakes in a bowl. Toss to mix. (This can be made a day ahead and refrigerated.) Toss in the tomatoes.
Step 2To serve, spoon the shrimp salad on warm bruschetta slices, dividing evenly. Garnish with dill sprigs. Serve immediately.