Drain the snails and place them in a saucepan with the white wine. Season with salt and pepper and simmer for 2 minutes. Drain the snails with a skimmer and boil the wine until only 2 tbsp. remain.
Preheat the oven to 220 °C
Peel and chop the shallots, garlic and parsley. Mix them with the walnut kernels, butter and reduced juice.
Divide the snails into 4 small cassolettes and sprinkle them with the nut butter