1. Infuse the olive oil with the vanilla: Heat the oil to 50° C for three minutes with the seeds scraped from the vanilla bean, as well as the bean itself which has been cut into pieces. Set aside.

Sauce

1. In a saucepan over low heat, place two tablespoons of olive oil, the finely chopped green onion and the sprigs of dry fennel;
2. let cook for a few minutes without letting it colour, then add 250 ml water, the crushed garlic and the powdered chicken stock, season with salt and pepper. Continue cooking, covered, over low heat for 10 minutes.
3. Remove the fennel sprigs, then whisk in the softened butter and a drizzle of lemon juice. Correct the seasoning.

Cooking and Presentation

1. Grate the zucchini on a mandolin to make fairly large spaghetti.
2. Sauté the zucchini quickly with a tablespoon of olive oil in a non-stick pan, season with salt and pepper, cover and stir often so that it does not brown.
3. After three minutes add the finely chopped basil and mix. Set aside.
4. Sauté the sea bass fillets in a tablespoon of olive oil, season with salt and pepper and let cook for 1 to 2 minutes on each side, depending on the thickness.
5. Divide the zucchini spaghetti among four plates and arrange the sea bass fillets on top. Squeeze a little lemon juice over each one, spoon the sauce around the fish and drizzle with the vanilla-scented olive oil.