1. Shell the shrimp and sauté the heads and shells in butter, then pour white wine over them. Once boiling, add 40 cl of water, the bouquet garni, and the minced onion.
2. Let simmer uncovered for 20 minutes.
3. Meanwhile, peel the carrots and cut them into sticks. Blanch the tomatoes, peel them, cut them in half, and squeeze them to remove the seeds. Cut the tomato flesh into quarters.
4. Strain the shrimp broth and bring it to a boil again. Add the carrots and tomatoes and cook for 15 minutes. Season with salt and pepper.
5. Mix the heavy cream and cornstarch together and incorporate them into the shrimp broth and vegetables. Stir and let thicken for a few minutes.
6. Then add the shelled shrimp and lemon juice. Let heat for a few moments.
7. Serve hot. Enjoy your meal!