Preheat the oven to full whack (240ºC/475ºF/gas 9). Peel 3 cloves of garlic and bash well in a pestle and mortar with half the thyme leaves and a good pinch of sea salt and black pepper, then muddle in a good splash of oil. Rub all over the chicken, getting into all the nooks and crannies. Halve the lemon and place in the cavity with the remaining thyme sprigs. Season the duck all over, rub with a good drizzle of oil, then finely grate over half the cinnamon stick. Place the rest of the stick in the cavity with the sage. Reserving the herby tops, trim and halve the fennel, then place in a large roasting tray with the whole, unpeeled onions and the remaining garlic cloves. Sit the chicken and duck on the top shelf of the oven, directly on the bars, with the fennel tray underneath. Turn the temperature down to 180ºC/350ºF/gas 4 and cook for 1 hour 30 minutes, or until the chicken is tender and the juices run clear. Pick the leaves from the rosemary sprigs into the pestle and mortar, then bash and bruise with a good splash of oil. Season the pigeons, partridges and quails all over, then drizzle with the rosemary oil. Gently untwist the links between the sausages and push the meat along to make one giant sausage. Start curling one end in, then twirl the sausage round itself until you have one big spiral of sausage, poking in the bay leaves. Sharpen the ends of the rosemary sprigs, then use them to skewer and secure the sausages in place. Drizzle with oil. Once the chicken is cooked, remove to a plate, cover with tin foil and a clean tea towel, then leave to rest. Place the rest of the birds directly on the oven shelf next to the duck. Sit the sausage wheel on top of the veg in the tray, then cook it all for 30 minutes, or until the birds are tender and cooked through. Meanwhile, to make the gremolata, peel the garlic, finely chop with the parsley leaves, then place in a bowl with the reserved fennel tops. Finely grate over the lemon zest, add a squeeze of juice and mix well. Remove the cooked birds from the oven and leave to rest. Move the roasting tray to the top shelf for a further 15 minutes, or until the sausage is cooked through and golden. Meanwhile, bring 1.1 litres of water to the boil in a large pan, then gradually add the polenta, whisking continuously until combined. Continue to stir over the heat for 15 to 20 minutes, or until oozy, thick and smooth. Transfer the cooked veggies and sausage wheel to a plate, then skim away and discard the fat from the tray. Place on a medium heat on the hob, stir in the flour for 1 minute, then pour in the Chianti. Scrape up all that goodness from the bottom of the tray, then add the plum tomatoes, any resting juices from the chicken and the stock. Bring to the boil, then simmer for 5 minutes, or until thickened and reduced to a lovely gravy consistency. Stir the butter into the polenta and finely grate in the Parmesan, loosening with a little water, if needed. Season to taste. Carve up the birds and slice the sausage, squeeze the onions and garlic out of their skins, then serve it all up on a board with the polenta. Scatter over the gremolata and serve the gravy and some steamed greens on the side.