Pumpkin mousse: season the pumpkin puree with salt, pepper, finely chopped rosemary and a drizzle of oil, then mix.
Ricotta mousse: mix ricotta with a pinch of salt, pepper, grated parmesan, a drizzle of oil and thyme.
Put each mousse in a sac à poche. Distribute some tuna on the bottom of glasses, add the pumpkin mixture and some finely chopped thyme.
Squeeze the ricotta mousse, decorate with thyme and more tuna chunks and truffle. Garnish with a thyme small branch, then serve.