The finished recipe. Cold Roast Beef and Watercress Salad with HorseradishIngredients 1 to 6. 140 g Lean beef, trimmed (Leftover from a roast is what this is for. Otherwise sear a steak, rest it and slice it cold. Weighed raw. The same piece weighed after cooking has lost water, so the protein per gram is higher and the total would come out about a quarter over.). 60 g Watercress. 100 g Cooked beetroot (Vacuum-packed, not pickled. Pickled beetroot carries vinegar and usually sulphites.). 40 g Gherkins. 30 g Red onion. 2 tsp, about 12 g Creamed horseradishIngredients 7 to 10. 40 g Greek yogurt, 0% fat. 5 g Olive oil. A tablespoon Cider vinegar. To taste SaltStep 1. If cooking from raw, season the beef, sear it in a very hot dry pan for two and a half minutes a side, rest it and let it cool before slicing thinly.Step 2. Slice the onion thinly and leave it in the vinegar with a pinch of salt for ten minutes.Step 3. Whisk the yogurt and horseradish together. Whisk the oil into the onion and vinegar.Step 4. Toss the watercress in the oil and vinegar, lay the beef, beetroot wedges and sliced gherkins over, and spoon on the horseradish.