Step 1In a blender or food processor, add the egg, garlic and Dijon. Let the blender run for 30 seconds, then slowly (drop by drop) add the grapeseed oil until it starts to thicken. (If it gets too thick, add a little water.)
Step 2Add the shallots, tarragon and chervil; blend. Add one-fourth teaspoon salt, one-eighth teaspoon pepper and the vinegar; blend.
Step 3Stir in the grated egg and cornichons. Adjust salt and vinegar to taste. Makes 1 1/4 cups.
Step 1Combine the vinegar, olive oil, walnut oil, onion and garlic in a blender until emulsified. Adjust salt and pepper to taste. Makes 3/4 cup.
Step 1Heat the oven to 350 degrees. Toss the bread in the melted butter, garlic, thyme and olive oil. Bake for 10 to 12 minutes until the croutons turn a nice golden brown. Set aside.
Step 2In a medium pot, blanch the beans in salty boiling water until their raw flavor is gone but they are still crunchy, 2 to 4 minutes. Shock them in a salty ice bath; drain. Set aside.
Step 3Put the tarragon aioli and walnut vinaigrette in a bowl and mix well. Add the croutons, grated egg, shallots, chervil, chive, tarragon and dill. Coat everything well with the dressing. Add the beans and mix well.
Step 4Finish with the lemon zest and the Parmesan and nuts, if using, and a little more vinaigrette if needed. Season with salt and pepper to taste and garnish with chervil, chive, tarragon and dill. Divide the salad among four plates and serve.