Technical Stages :

• Clean, scrub and drain carefully the shells.
• Cut in a fine brunoise the carotts and onions. ciseler the shallots. Remove the stem and crush the cloves.
• Prepare a bouquet garni.
• Put the oil and butter in a skillet over strong heat. Sweat the vegetables (onions+carotts+shallots).
• Add the shells.
• Sauté until they turn to a bright red.
• Remove the fat. Flambé with brandy. Add the white wine and reduce. Moisten with the fish broth.
• Add the crushed tomatoes, tomato paste, garlic, bouquet garni and tarragon.
• Season with salt and cayenne pepper.
• Cook uncovered for 30 minutes, skimming if necessary.
• When finished, filter the sauce through a chinois, packing.
• Reduce by half. Bind the sauce with cornstarch or kneaded butter.
• Cook for another 10 minutes. Season.
• Filter through a chinois and whisk with butter.