Preheat the oven to 200°C / 400°F / Gas mark 6.
Prepare a roasting tin with kitchen foil and set aside.
Prepare a baking tray with greaseproof paper and set aside.
Put the spinach in a large colander and pour over 1-2 kettles of boiling water to wilt.
Allow to drain for a few minutes, then press out as much excess water as possible.
Chop the spinach roughly, put it in a bowl and mix in the ricotta, lemon zest, nutmeg and plenty of salt and pepper.
Blitz 2 slices of bread in a food processor until breadcrumbs are achieved.
Using a sharp knife, cut a slit into the side of each chicken breast and use your fingers to make a little pocket.
Spoon the mixture into the fillets.
Rub with 2 teaspoons of the oil and press the breadcrumbs on top, then arrange the chicken in the roasting tin.
Put the vegetables on the prepared baking tray and drizzle with the remaining oil, and season well with salt and pepper.
Bake for around 30 minutes, stirring the vegetables midway through.
Remove when the chicken is cooked through and the breadcrumbs are golden.
Remove the softened garlic from the vegetables and mash it with the lemon juice, then stir this with the roasted vegetables and serve with the chicken.