Using a julienne scraper, grate zest from a quarter of the limes; set aside with lid closed. Squeeze 2/4 of the limes.
Make 6 tbsp lime juice (based on 4 servings), water, dried tarragon, peppercorns and salt 6-8 min, pour through a sieve into a saucepan.
Cut the monkfish fillet into 4 pieces per unit. Remove each shrimp from the shell, cut in half lengthwise and remove the intestines. Mix the egg yolks with one-eighth of a liter of tarragon stock and the cornstarch and set aside.
Bring the remaining tarragon stock to a boil. Pour in the fish pieces and cook at low temperature in the closed saucepan for 2-3 minutes. Add the crab tails and cook with the monkfish for 1 more minute. Lift out the fish and crab tails with a skimmer and place in a large enough bowl. Add the whipping cream to the broth form and bring to a boil. Mix in the egg yolk broth with a whisk and heat for 1-2 min, stirring throughout, to create a creamy sauce. Season the sauce with sugar and add a little salt if necessary. Mix the fish pieces and the crab tails into the sauce. Can be served, for example, in puff pastry patties.