Cook quinoa: bring to a boil 600 ml of water, salt slightly, pour the quinoa previously rinsed and cook for 15-20 minutes stirring occasionally. At the end of cooking the water will be completely absorbed.
In the meantime, grate the courgettes with a large grater and season with the juice of half a lemon, oil, salt, pepper and a few leaves of marjoram. Cut the cherry tomatoes and season with oil, salt, pepper, some basil leaves and the Taggiasche olives cut into rounds.
When the quinoa is cooked, remove from the heat, season with vegetables and put it in Freddy with the blast chilling function for about 20 minutes. Blanch the tuna in a very hot pan for 1 minute per side and blast chill it in Freddy along with the quinoa.
Cut the tuna into slices, season with a pinch of pepper and a drizzle of oil and serve over the quinoa cold.