Cook the cubes of lardo or pancetta in a large casserole over a moderate to high heat until they give off enough fat to fry the pork.
When the fat is hot add the cubed pork( in batches if necessary) and leave to colour lightly, stirring occasionally. Remove each batch as it turns golden.
Add the sausages and brown them lightly, then remove. Cook the onions and garlic, with a couple of bay leaves and some thyme sprigs, in the fat for 10-15 minutes until they are soft and golden.
Put the pork and sausages back into the pan with the onions, season with a little salt and pepper and cover tightly. Put into a preheated 180 C, gas 4 oven for 30 minutes.
Add the lentils to the dish with hot stock or water, Return to the oven, covered and cook for 40 minutes or so until tender. Remove, stir and season- it will need salt and pepper and perhaps lemon. Scatter over the parsley and serve.