Season chicken thighs with salt and pepper, and dust with flour.

Melt 30g butter in casserole dish. Sear chicken until golden brown, then set aside.

Add onions, leek and garlic to pan and cook till translucent ~15mins.

Preheat oven to 100.

Pour sherry into the onion pan and bring to the boil. Set on fire. Reduce heat, add chicken stock and cream. Simmer for 20 mins.

Return chicken to pan and simmer. Cover dish and place in oven. Bake for 45 mins.

Cool dish. Remove chicken. Strain sauce through a fine sieve and discard veggies. Put sauce back in dish and reduce by half, skimming off impurities.

In a frypan melt half the remaining butter until foaming. Sprinkle the baby onions with salt, pepper, sugar and the thyme leaves. Brown on the flat side and remove.

Add remaining butter to the pan and caramelise mushrooms till golden. Season during this. ~15-20 mins.

Add onions and mushrooms to casserole with reduced sauce and simmer for 2 mins.

Render fat out of bacon on medium heat fry pan. Drain on paper towel.

To serve add Parmesan, Gruyere, mustard and truffle oil to casserole. Season with salt and pepper. Add thigh fillets and heat for 10 mins on medium.

Serve with bacon and freshly chopped herbs.