Zest the lemon, bash the garlic cloves (but leave them whole) and roughly chop the oregano (stalks and all). Butterfly the chicken or cut into strips. mix everything together, along with the olive oil and black pepper (but not the salt). Leave to marinate for several hours, better still overnight.
Peel and dice the onion, garlic, celery and carrot. Sweat in olive oil for around 5 minutes adding a pinch of maldon sea salt if starts to catch. Add the lentils, bay leaf and thyme, cover with stock and simmer until the lentils are tender. Add more stock during the cooking if required. Add the spinach and stir through to wilt. Finish with a squeeze of lemon, the seasoning and freshly chopped parsley.
In a bowl whisk together the lemon juice, vinegar, mustard, salt and pepper. Slowly whisk in the oil so the vinaigrette starts to emulsify (get thicker). When you have the correct consistency finish with finely chopped oregano. Pour in to a squeezy bottle.
Get a griddle pan very hot. Season the chicken with salt and grill on both sides until nicely charred and just cooked through. Serve with the lentils and a dressing of vinaigrette.
«This is even better on a barbecue. It is great served cold for lunch the next day.»