For salad, cut off the root of the lettuce and separate leaves. Place the leaves in a large salad bowl with blanched peas.

Just before the chicken and potatoes are done roasting, prepare beurre blanc by combining wine, shallot, peppercorns, bay leaf, and the 1/2 teaspoon salt to a saucepan; place over medium heat. Simmer until sauce is syrupy and just coats the bottom of the pan. Add butter slices, a few at a time, while stirring with a whisk to thicken the sauce and give it a shine. Add salt and pepper to taste. Dress lettuce and peas with some of the warm beurre blanc. Toss so the leaves wilt a little.

To serve the complete dish, add the 10 warm chicken pieces and the potatoes to the salad and gently toss to combine. Finish with another drizzle of beurre blanc.

To blanch the peas, submerge them in boiling salted water for about 2 1/2 minutes (for fresh peas). Strain them and immediately plunge them into ice water to stop the cooking process. Strain them again and set aside.