Heat olive oil in large heavy based pan. Fry onion, celery, garlic and chilli for about 5 mins over a gentle heat until softened
Add tomato paste and cook for about 2 - 3 minutes
Add lentils and stir well to coat in tomato mixture
Add fresh tomatoes and cook for about 1 - 2 minutes
Add bacon hock or ribs, tinned tomatoes, bay leaves and stock and stir to combine. Season with salt and pepper. Bring to a gentle simmer and cook for about 2 hours, stirring from time to time. Can be cooked less but I find the longer you simmer the richer the flavour.
Finish by scattering fresh basil leaves and serve with hot, crusty bread.