Cut the butternut squash and onions into pieces.
Sauté  the onions and butternut squash in butter.
Add enough water to cover the butternut squash pieces.
Cook until done.
Sieve and collect the juice (you may need it later).
Blend the butternut squash into a fine purée in a blender (leave as thick as possible).
Cool the purée in the fridge.
Put 500 g of the purée and the 500 g of crème frâiche in a bowl and whip until the mixture retains its shape.
Season with avocado oil and pepper.
If you would like the mousse to have a firmer texture that can be cut, add the gelatine leaves.
(Soak the gelatine leaves in cold water. Heat up approx. 3 tbsp of butternut squash purée, add the gelatine leaves and stir well. Follow the recipe and complete the remaining steps.)

Serve with air-dried ham and Malax Loaf slices.