- ½ small white onion, very thinly sliced into rings
- 1 tablespoon fennel seeds
- 1 medium fennel bulb, thinly sliced into rings
- 1 bunch watercress, thick stems removed (or sub salad mix and sunflower sprouts)
- 2 tablespoons white wine vinegar
- Kosher salt, freshly ground pepper
- 2 tablespoons olive oil
Soak onion in a bowl of ice water 30 minutes; drain.
Toast fennel seeds in a dry small skillet over medium heat, tossing often, until golden, about 4 minutes. Transfer to a cutting board and coarsely chop.
Toss onion, fennel bulb, watercress, and vinegar in a large bowl. Season with salt and pepper, add oil and fennel seeds, and toss again to coat.