Put the new potatoes on to simmer in a pan of boiling water until tender. Cut the asparagus in half to shorten the spears and slice the ends without the tips. Tip the bouillon into a wide non-stick pan. Add the asparagus and beans, then cover and cook for 5 mins.

Add the peas to the pan, then top with the trout and lemon slices. Cover again and cook for 5 mins more until the fish flakes really easily, but is still juicy.

Meanwhile, mix the yogurt with the vinegar, mustard powder, mint and dill. Stir in 2-3 tbsp of the fish cooking juices. Put the veg and any remaining pan juices in bowls, top with the fish and herb dressing, then serve with the potatoes.