1 Remove the legs from the crown of grouse. Next, heat a tablespoon of oil in a pan and fry the legs with some salt and pepper. Once they are browned, place them in a warm oven (180C/Gas Mark 4) to cook for 45 to 50 minutes. They take a bit longer than the breasts to cook due to the sinews.
2 Next, dice the squash into 1-inch chunks and place in a roasting tin with the red onion pieces, half the thyme and half the garlic. Drizzle with half the remaining oil and season with salt and pepper. Roast alongside the legs for 40 to 50 minutes until soft and browned.
3 Roast the grouse crowns on the bone. Heat the remaining oil in a frying pan and get it quite hot. Then fry the crowns with some salt and pepper before adding the potatoes and the remaining garlic and thyme, and the duck fat.
4 Ensure you turn the potatoes and the grouse all the time whilst colouring on the hob. Once browned, add the butter and place in the oven for 8 to 10 minutes. No more. Grouse should always be quite rare and never over cooked. Remove from the oven and allow them to rest before removing the breasts from the carcasses.
5 Remove the squash and onion from the oven and add the spinach to the roasting tin, allowing it to wilt in the residual heat. Add the potatoes, the sweet garlic cloves and the thyme, mix and place into the centre of warmed plates.
6 To serve, either slice the grouse breasts into smaller pieces or place a whole one on each plate. Place the leg on top and trickle each dish with the pan juices. Serve immediately.