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White Onion, Fennel, and Watercress Salad

This vibrant white onion, fennel, and watercress salad is a masterclass in balancing sharp, peppery, and aniseed notes. A refreshing vegan side dish, it relies on simple preparation to let the quality of the seasonal ingredients shine. Soaking the onions in ice water is a clever professional trick that removes the harsh raw bite, leaving behind a subtle sweetness that pairs beautifully with the crunch of the raw fennel bulb.

Light and zesty, this salad makes an excellent accompaniment to grilled fish, roasted vegetables, or as part of a summer spread. The addition of toasted, coarsely chopped fennel seeds provides a layer of earthy warmth and nuttiness, elevating the dish into something truly sophisticated. It is a healthy, naturally gluten-free option for those seeking a crisp and flavourful green salad.

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Ingredients for White Onion, Fennel, and Watercress Salad

  • 1/2 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

  • 2 tablespoons white wine vinegar

  • Kosher salt and freshly ground black pepper

  • 2 tablespoons olive oil

How to make White Onion, Fennel, and Watercress Salad

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.

Disclaimer

While every effort has been made to ensure the information is accurate and up to date, individual needs may vary and dietary requirements can differ based on personal health conditions. Always check food labels and allergen information before preparing or consuming any recipe. If you have specific health concerns, allergies, intolerances, or are following a medically prescribed diet, seek advice from your GP, pharmacist, or a registered dietitian before making significant changes to your diet or lifestyle.

Article history

The information on this page is peer reviewed by qualified clinicians.

  • 16 Jan 2026 | Originally published

    Authored by:

    UK recipe editors

    Peer reviewed by

    UK recipe editors
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