To make the dressing - lightly whip the cream with the rest of the ingredients, and some salt and pepper. Set aside.
Bring a pan of water to the boil, add the potatoes, reduce the heat, cover and cook for 8 mins. Add the carrots and cook for 2 mins. Place the asparagus and mange tout in a steamer above the potatoes and carrots, and cook everything for another 3 mins.
While the vegetables are cooking, dry fry the seeds for 2-3 mins until beginning to brown and pop. Remove from the heat and stir in the sumac and some sea salt.
Arrange the vegetables on a large platter, scatter with mint and the toasted seeds before drizzling with the dressing and adding some zested lemon strips.
Recipe by appetite magazine at https://www.appetitemag.co.uk/jersey-royal-salad/