French Onion Chicken

Thinly slice 5 large brown onions (about 1‑1.25 kg).

Heat 40 g butter and 1 tbsp olive oil in a large oven‑proof pan, add the onions with a generous pinch of salt, and cook gently for 45 minutes to 1 hour until deeply golden and caramelised.

Add the 4 sliced garlic cloves and 4 thyme sprigs, cooking for another minute.

Stir in 1 tbsp plain flour, then pour in 150 ml dry white wine, scraping the pan bottom, and reduce the liquid by half.

Add 300 ml beef stock, 1 tbsp Worcestershire sauce, 1 tsp Dijon mustard and 2 bay leaves; simmer for 5 minutes until slightly thickened and season to taste.

Pat the 1.6‑1.8 kg chicken dry and spatchcock it.

Mix 30 g softened butter with 3 grated garlic cloves, 1 tsp fresh thyme leaves, salt and pepper; spread the butter under the chicken skin and rub the outside with 2 tbsp olive oil, then season generously with salt and pepper.

Place the chicken skin‑side up on the bed of caramelised onions and roast at 400°F fan‑assisted for 45‑60 minutes until the skin is golden and the meat is cooked through.

Scatter 200 g grated Gruyère over the onions around the chicken, leaving the crispy skin exposed, and grill for 2‑4 minutes until the cheese is melted, bubbling and golden.

Rest the chicken for 10 minutes, then finish with fresh thyme and black pepper, carve and serve with buttery mashed potatoes and plenty of the cheesy French onion gravy.