This is a prawn and avocado salad built on the bones of a classic prawn cocktail — same Marie Rose-style dressing, same cold prawns, but with avocado and fresh dill doing more of the work so you need far less sauce. It comes together in about 20 minutes with no cooking required beyond a quick five-minute marinade. If you want a proper lunch that doesn’t heat up the kitchen, this is a reliable one.
The technique that matters
The only technique worth slowing down for is the prawn marinade. Tossing the cooked prawns with lemon juice, dill, salt, and pepper for five minutes before you plate them makes a real difference — the acid firms the texture slightly and the dill flavor gets into the prawns rather than just sitting on top. Don’t skip it, but don’t over-marinate either; beyond ten minutes the lemon starts to break down the texture. The second thing: dress the prawns and the greens separately. If you pour the Marie Rose dressing straight over everything at once, the lettuce wilts fast and the avocado turns slippery. Keep the dressing on the side until you’re ready to eat, or spoon it only over the prawns just before serving.
Make-ahead notes
You can make the dressing up to three days ahead — whisk it together, cover, and refrigerate. The prawns can be marinated up to two hours in advance and kept covered in the fridge. Slice the avocado no more than 30 minutes before serving; a squeeze of extra lemon juice on the cut surfaces slows browning but won’t stop it entirely past that window. The cherry tomatoes and red onion can be prepped several hours ahead and stored separately. Do not assemble the full salad in advance — once the avocado is plated with the greens and dressing, it doesn’t hold. This one is best built right before it hits the table. Freezing is not suitable for any component of this dish.
If something goes sideways
- Dressing tastes flat or too sweet: The ketchup can tip the balance depending on the brand. Add a small extra squeeze of lemon juice and a pinch more cayenne — that usually pulls it back into shape without thinning the texture.
- Prawns are watery on the plate: Cooked prawns from a bag often release liquid. Pat them dry with paper towels before the marinade step. Skipping this is the most common reason the dressing ends up diluted.
- Avocado is underripe: A firm avocado won’t slice cleanly and the flavor is bland. If that’s what you have, skip the garnish — not worth the extra dish — and instead dice it small and toss it with the lemon juice from the marinade so it absorbs more flavor.
- Salad is too sharp or acidic overall: You’re using lemon juice in both the marinade and the dressing. If the combined result is too sharp for your taste, cut the dressing lemon juice to half a teaspoon and rely on the Worcestershire for depth instead.
- Red onion is too harsh: Raw red onion can overpower everything else. Soak the sliced onion in cold water for ten minutes, then drain and pat dry before adding it to the salad. It keeps the crunch but loses most of the bite.
British Prawn and Avocado Salad
Equipment
- Mixing bowl
- Knife
- Cutting board
- Small Saucepan
- Whisk
Ingredients
For the Salad:
- 7 oz cooked North Atlantic prawns, peeled and deveined cold water prawns preferred for sweetness
- 1 large ripe avocado peeled, pitted, and sliced
- 2 cups baby gem lettuce washed and shredded
- ½ cup cherry tomatoes halved
- ¼ cup thinly sliced red onion or shallot, for milder flavor
- 1 tbsp fresh dill chopped, plus more for garnish
- 1 tbsp lemon juice freshly squeezed
For the Dressing:
- 3 tbsp mayonnaise preferably free-range egg mayonnaise
- 1 tbsp ketchup classic tomato ketchup
- 1 tsp Worcestershire sauce
- 1 tsp lemon juice additional for dressing
- 1 pinch cayenne pepper optional, for gentle heat
- 1 pinch black pepper freshly ground
- 1 pinch salt to taste
Instructions
- In a small bowl, whisk together mayonnaise, ketchup, Worcestershire sauce, 1 teaspoon lemon juice, cayenne pepper (if using), and a pinch of salt and pepper. Adjust seasoning to your taste and set aside in the fridge.
- In a mixing bowl, gently combine the cooked prawns with freshly squeezed 1 tablespoon of lemon juice, a bit of salt, pepper, and chopped dill. Allow to marinate for 5 minutes.
- Prepare your vegetables: slice the avocado, halve the cherry tomatoes, shred the lettuce, and finely slice the red onion. Place into a large bowl or arrange directly onto serving plates.
- Spoon the dressed prawns over the bed of greens and vegetables. Drizzle with the prepared dressing or serve it on the side for a lighter option.
- Garnish with additional dill and a wedge of lemon. Serve immediately while fresh and chilled.
Notes
- For a lighter version, use Greek yogurt instead of mayonnaise in the dressing.
- To make it gluten-free, ensure the Worcestershire sauce is gluten-free certified.
- For additional crunch, serve with a slice of toasted sourdough or watercress on the side.
Nutrition
Common questions
Can I use frozen prawns instead of fresh?
Yes, frozen cooked prawns work fine here. Thaw them overnight in the fridge or under cold running water, then pat them completely dry before marinating — excess water is the main issue with frozen prawns in a salad like this.
What can I use instead of mayonnaise in the dressing?
Full-fat Greek yogurt is the most practical swap and keeps the dressing creamy without changing the overall flavor much. The texture will be slightly thinner, so start with two tablespoons and adjust from there.
Can I use regular iceberg lettuce instead of baby gem?
Yes, iceberg works and actually holds up a little better if the salad sits for a few minutes before eating. Shred it finely so it doesn’t feel too bulky against the prawns and avocado.
How do I know if my avocado is ripe enough?
It should yield to gentle pressure from your thumb without feeling mushy. If the small stem end pops off cleanly and the flesh underneath is green rather than brown, it’s ready to use.
Is this recipe suitable for someone with a shellfish allergy?
No — prawns are shellfish, and there’s no meaningful substitute that produces the same result. If you need to avoid shellfish entirely, a lemon-herb crab alternative would have the same issue; poached chicken or smoked salmon are the most practical protein swaps.
Can I double the recipe for four people?
Easily. The dressing scales up without any adjustment needed. Just use a large enough bowl for the prawn marinade step so everything gets coated evenly rather than sitting in a pile.
Try these next
- Fresh Lemon-Herb Crab Salad
- Sweet and Tangy Grape Chicken Salad
- Authentic Spanish Seafood Paella
- Classic British Lemon Curd
