Preheat the oven to 190C/375F/Gas 5.
Take four tablespoons of the diced butternut squash and blanch for 2-3 minutes, or until cooked but still firm.
Put the remaining butternut squash in a roasting tin with the garlic cloves and a little olive oil and season with salt and pepper. Roast for 20 minutes, or until very soft.
Transfer to a blender and add half the vegetable stock and two tablespoons of olive oil. Blend to a smooth purée, adding more stock if necessary. Taste and add more salt and pepper as required.
Season the spatchcocked quails with a little salt. Heat a tablespoon of olive oil in an ovenproof pan and brown the quail on all sides. This will only take 2-3 minutes.
Put the pan into the oven and roast for about four minutes. Remove from the oven and rest for five minutes. Check the meat is cooked through – the juices should run clear when the meat is cut into. The breast and legs might need more cooking. If so you can finish cooking them in the sauce.
Use the same pan to fry the lardons until crisp then set them aside. Fry the shallots until softened, add the chicken stock and cook until reduced in volume to a thick sauce (add the quail breasts and legs here if they need to cook a bit more). Put the cooked bacon back into the pan and add the vinegar and cooked lentils.
Fry the four tablespoons of blanched butternut squash in a little oil until golden-brown. Season with salt, pepper and the chopped rosemary.
Spread some purée on each serving plate, add some pieces of butternut squash, lardons and lentils then the quail, and the salad leaves. Serve a little extra sauce on the side.