- Combine the oil, lemon juice, tarragon, shallots and salt.
- Toss with the crab. Place in a covered container and refrigerate for several hours to let flavours blend.
- To serve, place an asparagus spear-half on each leaf of endive.
- Top with approximately 2-3 teaspoons Dijon Sauce and sprinkle with crab.
- Dijon Sauce: Place the egg yolks, vinegar, lemon juice, mustard, sugar, salt and pepper in a blender.
- Blend for a few seconds.
- With the motor still running, add the oil in a slow steady stream until well incorporated.
- Remove the sauce to a bowl and whisk in the Creme Fraiche.
- Cover and refrigerate.
This can be made several days in advance and kept in the fridge.
Leftover sauce is wonderful with chilled artichokes.