For the salad: Peel and thinly slice the zucchini and the onion. Mix with the snow peas and the spinach, then season with salt and pepper.
For the vinaigrette: Roast the cumin in a dry pan until it crackles, then taste to ensure it has a roasted flavor.
Crush the mint in a mortar. Blend in the olive oil, the lemon juice and the muscovado sugar, then season with salt and pepper.
Finally, blend in the cream and then mix into the salad.