*A 2.2 lb./1000g gives 10 ounces/300g of meat. You would need 2 crabs for this recipe. Avoid refrigeration prior cooking; it will tighten the flesh. Cook crab in a large amount of boiling water and salt ≈12L / 11qt and 100g salt. Throw in a couple of crushed garlic, fresh thyme, a bay leaf, and few peppercorns. Immerse crab, head first and when it begins to boil cook for 8 min per pound (450g). Remove crab from hot water and let drain bottom down for 10 min. let cool and process to clean, or refrigerate overnight.
Remove the apron that is located underneath. Push the body section out with your thumbs. Pull off mouth and gills, and discard. Remove and reserve the brown meat for the crab jus. Break down and remove and save meat from the body; save empty body for the jus. Twist off legs, and detach arm from the knuckles and claw. Spread claw backward, then the cartilage should come off easily and so the meat. Then, gently break all parts using a small rolling pin in order to free the meat using the tip of a paring knife, or a bamboo skewer. Once done, spread crab meat over a plastic wrap sheet, and pick through any remaining shell pieces and cartilages.
Soak gelatin in cold water to soften, and drain. Meanwhile, in a hot large sautoir (Shop Page), add oil and sauté for about 10 min the crushed crab body parts, brown meat, add some knuckles (no legs), salt, shallots, carrots, thyme, a bay leaf, and a few black peppercorns. Add wine and water, bring to a boil, and cook for 40 min on medium heat. Reduce crab stock to a 3/4 cup/200g jus. Remove from the heat, and transfer to a pastry bowl, whisk in gelatin and cool on ice water; stirring every so often. When it begins to set, remove from ice water. Keep it in the liquid stage – gently rewarm to liquid stage if necessary; it must remain liquid and cool prior mixing in whipped cream.
Use a 8.5’’/21cm diameter pastry ring. In a chilled mixing bowl, whip heavy cream to medium-firm peaks, and transfer whipped cream in a pastry bowl. Whisk some into the crab jus first, and add remaining whipped cream; whisk well. Place a pastry ring over a plater and fill it up; smooth out using an offset spatula. Chill overnight to set. Run a knife around the edges of the ring prior removal; keep refrigerated. The crab flan can be frozen for later use if desired.
Wash lettuce heart, and pat dry. Cut leaves using a round cookie cutter; reserve for the montage. Season crab meat with some chopped tarragon and savory (sariette), add olive oil, grapefruit juice, salt and pepper to taste; chill.
Arrange grapefruit segments over the chilled crab flan, and the lettuce leaves, then the crab salad. Since the crab flan is crust free, spoon out to serve. Crab flan can be kept 2 days in the refrigerator. Enjoy!