A note on crayfish: They're good in spring and summer, best bought from a reliable supplier and, ideally, purchased live. If you can't find them live, opt for freshly cooked and peeled ones and skip the boiling step in the recipe. And, yes, you can replace crayfish with shrimp.
1. Peel the grapefruit, reserving the rind for cooking the crayfish. Using a small knife, slice away the bitter pith and with it the thinnest possible layer of fruit. Cutting against the membranes, release each section of grapefruit intact; remove any seeds. Set the sections aside for the moment and, working over a bowl, squeeze as much juice from the membranes as you can, to use in the cocktail sauce; discard the membranes.
2. Halve, pit and peel the avocados, then rub the exposed fruit with the cut lemon to keep it from darkening. Slice each avocado half into 3 wedges and give the wedges a squirt of lemon juice.
3. Arrange the lettuce in an even layer in the bottom of a large shallow bowl. Mound the tomatoes in the center of the bowl and surround them with alternating slices of grapefruit and avocado. Sprinkle the tarragon over the tomatoes. Cover the salad and keep it refrigerated until serving time. (The salad can be made a couple of hours ahead of time and kept tightly covered and chilled.)
1. If the crayfish are cooked and peeled, move on to the cocktail sauce. If they're live, bring 1 gallon of water to a boil in a stockpot. Add all the ingredients, return to the boil, and simmer, uncovered, for 2 minutes. Remove the pot from the heat and cool the crayfish in the water for 10 minutes. Drain and discard the cooking liquid.
2. To peel crayfish, twist off and discard the head. Peel off the upper three sections of shell, then, holding the meat in one hand and the tip of the tail in the other, squeeze the tail while pulling the meat out of the shell. The vein in the center of the crayfish should come off with the shell. If it doesn't, remove it by hand, then use your finger to rub off any yellow coral that clings to the meat. Set the crayfish aside.
The Cocktail Sauce:
1. Boil the grapefruit juice until it is reduced to 2 teaspoons; cool.
2. Whisk the yolk, mustard, salt and pepper to taste, and cayenne together in a medium bowl. Whisking constantly, add the oil in a slow stream. When the mixture is emulsified, like mayonnaise, whisk in all the other ingredients, including the cooled grapefruit juice. Taste and adjust the seasonings if necessary. (The sauce can be kept in a tightly covered container in the refrigerator for 2 to 3 days.)
To serve: Arrange the crayfish on the tomatoes sprinkle with almonds, and serve the sauce on the side.
To drink: A light, dry Alsatian Gewurtztraminer or, perhaps, a Muscat Sec.
This recipe was provided by a chef, restaurant or culinary professional. It has not been tested for home use.
Recipe courtesy of Daniel Boulud's Cafe Boulud Cookbook. Published by Scribner, 1999