Rhubarb has an amazing flavour spectrum – one that floats, skips, jumps and crashes right over your tongue, from the front to the sides and back again. It's incredibly tart and refreshing, so eating rhubarb is a great way to finish your meal, but it's also just as brilliant as part of the main event – something we don't often think about.
There are two different types of rhubarb available: forced and naturally grown. Forced rhubarb is grown earlier in the season, in warm, dark conditions away from the elements, to give you stalks that are brighter in colour, more tender and with less stringiness than the field-grown stuff. But in my opinion, each variety tastes as delicious as the other. Look for nice firm stems, and remember to chuck the inedible leaves if they're still attached.
Regardless of how you cook rhubarb, you've got to balance its extreme sourness and acidity with sweetness. This can make for some interesting – and truly brilliant – flavour combinations, which my recipe this week is all about. Cooking a whole salmon might seem a bit daunting, but it's actually incredibly easy. Poaching it slowly like I've done here means you can leave it to do its thing, while you get on with putting a bit more effort into the sides and sauces – zingy tarragon mayo, tangy rhubarb sauce and pickled onions will create an impressive springtime spread.
Servings: Serves 10
1 2.5-kilogram (5.5 pounds) whole salmon, gutted and scaled, from sustainable sources
2 sticks of celery
3 fresh bay leaves
1 tablespoon black peppercorns
1 tablespoon pink peppercorns
Pickled red onions
2 small red onions
1/4 cup red wine vinegar
A few sprigs each of fresh flat-leaf parsley, tarragon, chervil and mint
5 sticks forced rhubarb
1 small apple
2 tablespoons liquid honey
1 fresh bay leaf
3 whole cloves
1 splash red wine vinegar
1 orange, juice only
200 grams fresh tarragon
300 mL oil (a mixture of olive
and vegetable oil works best)
2 large free-range egg yolks
1 heaping teaspoon Dijon mustard
1-2 tablespoons white wine vinegar
To poach the salmon, place it in a large roasting pan. Cover with cold water and place the pan over two burners on the stove.
Peel and roughly chop the onion and carrots, then trim and roughly chop the celery. Place in the water with the salmon.
Add the bay leaves and the black and pink peppercorns. Cover with a lid or aluminum foil and bring to a boil.
Switch off the heat and allow the water and salmon to cool for about 5 hours.
For the pickled red onions, peel and finely slice them, ideally using a mandolin (use the guard), then place in a small bowl.
Add the red wine vinegar and a pinch of sea salt, scrunch together, then set aside to allow the onions to turn pink.
Meanwhile, make the rhubarb sauce.
Trim the rhubarb, peel and core the apple, then chop both into 1-inch chunks. Place the fruit in a pan with the honey, bay leaf and whole cloves. Add a splash of vinegar and the orange juice.
Bring to a boil, then turn the heat down to medium. Cover and leave to cook for about 30 minutes, or until the rhubarb has softened. Add a little extra honey to sweeten, if necessary. Tip into a bowl and set aside to cool.
To make the mayonnaise, first make a tarragon oil. Pick the tarragon leaves into a blender, add 100 mL of oil and blitz to a pulp. Add the rest of the oil and blitz again, then strain through a double piece of cheesecloth into a jug.
Place the egg yolks in a mixing bowl with the mustard and whisk well. Very slowly drip the tarragon oil into the egg yolk as you whisk; when you’ve added half of the oil, add 1 tablespoon of vinegar, then continue whisking in the oil (you might not need all of it). Finish with a squeeze of lemon juice and season to taste with salt and black pepper.
Carefully remove the salmon to a serving board and gently remove the skin. Break up the salmon flesh into random lobes and arrange on a large platter, then rub them with a little oil. Pick the herb leaves off the stems, add to the onions and toss well.
Serve the poached salmon with the pickled onions, rhubarb sauce and tarragon mayo on the side. Always good with some lovely boiled new potatoes, and a fresh green salad.