Method
If you are using ricotta from a tub, tip it into a sieve, break it up a little with a fork, cover and leave to drain over a bowl overnight. Ricotta from a tub is a bit wetter than the fresh stuff, which is more dry and crumbly.
To spatchcock the bird, place it on a chopping board, breast-side down. Using a pair of poultry shears or strong kitchen scissors, cut down the centre of the backbone so the skin remains firmly attached to the bone on either side. Turn the chicken breast-side up, open it up and then, using the heel of your hand, press firmly along the breast bone so that you break it and the wishbone to make the bird lie flat. Then, starting at the neck end, carefully push your fingers between skin and flesh, first over one breast and leg, then the other, leaving the skin attached at the end of each leg.
For the stuffing, tip the ricotta into a bowl and mash with a fork. Add the garlic, chopped herbs, lemon zest, Parmesan, egg, ½ tsp salt and some pepper, and mix well. Stir in the breadcrumbs.
Preheat the oven to 180°C/fan160°C/Gas 4. With one hand, lift the chicken skin away from the flesh. With the other, spoon small amounts of stuffing over the flesh of the legs and then the breasts, making sure there is an even layer over all the meat. Secure the skin in place at the neck opening with small, fine trussing skewers or cocktail sticks. From the outside, smooth and shape the stuffing over the bird so that it takes on its natural shape.
Scatter the thyme sprigs and bruised garlic cloves down the centre of a lightly oiled roasting tin and place the chicken on top, breast-side up. Brush it with oil, season and transfer to the oven. Roast for 1 hour, or until the juices run clear when the thickest part of the meat is pierced with a skewer.
Lift the chicken onto a board and leave it to rest for 5 minutes. Meanwhile, place the roasting tin over a medium-high heat, add a couple of tablespoons of water and deglaze the tin, scraping with a wooden spoon. Strain the juices into a small pan, skim away the excess oil and keep warm.
To serve, cut the chicken in half down the breast bone and then cut off each leg along the crease between the thigh and the body. Then, if you wish, separate the drumstick from the thigh at the joint and cut each breast into two. Serve with the cooking juices, and baby carrots tossed in summer herb butter.