*To spatchcock the chicken: Place the bird, breast side down on a cutting board. Using poultry shears or a sharp knife, score along both sides of the backbone, cutting through the skin and bone. Remove the backbone. Turn the bird over and press firmly on the breast bone to break it, and flatten the breast. Tuck the wing tips under the breast. Set the chicken aside.
In a large bowl, mix together the ricotta, chervil, chives, lemon zest, and season with sea salt and black pepper, to taste. Using your fingers, carefully loosen the skin over the breast of the chicken and down to the thigh area. Spread the ricotta mixture evenly under the skin to coat the breast and thigh meat.
Set the chicken in a roasting pan, drizzle it with olive oil and re-season with salt and black pepper, to taste. Roast until the juices run clear when you poke a skewer into the thickest part of the thigh, about 50 minutes. Let the chicken rest for 5 minutes before carving.