- 2 pounds small shell-on shrimp
- Kosher salt
- 2 fennel bulbs sliced crosswise ¼-inch thick, fronds reserved
- 1 English hothouse cucumber sliced ¼-inch thick
- 1 small red onion very thinly sliced into rings
- 1 tablespoon finely grated lemon zest
- 1/4 cup fresh lemon juice or more
- Coarsely ground black pepper
- 1/3 cup olive oil
- 1/2 cup dill sprigs
- Cook shrimp in a large pot of simmering salted water until bright pink and cooked through, about 3 minutes. Drain and let cool.
- Peel and devein shrimp and place in a large bowl. Add fennel, fennel fronds, cucumber, onion, and lemon juice and toss to combine; season with salt and pepper. Drizzle with oil and toss to coat.
- Add dill and lemon zest and toss again; season with salt, pepper, and more lemon juice, if desired. Top with more pepper just before serving.
Do Ahead: Salad can be made 4 hours ahead. Cover and chill.