For the cheese dumplings, place the smoked ricotta, mashed potato and egg into a bowl and mix well to combine.
Add the flour and mix to form a dough. Season well with salt and freshly ground black pepper.
Roll the cheese mixture into 3cm-4cm/2in-2½in balls.
Place the cheese dumplings into a pan of boiling water and cook until they rise to the surface of the water.
Remove the cheese dumplings with a slotted spoon and drain on kitchen paper.
For the casserole, heat the oil in a pan over a medium heat, then fry the onion, garlic, carrot, celery, red and green pepper until just soft.
Add the wine and the lemon juice and zest and bring to the boil. Cook until the liquid has almost completely reduced.
Add the lentils and stock and bring to the boil. Reduce the heat and simmer for 20-25 minutes, or until the lentils are cooked through but still a little al dente.
Add the parsley and season, to taste, with salt and freshly ground black pepper.
To finish the cheese dumplings, melt the two tablespoons of butter in a frying pan over a medium heat.
Add the cheese dumplings and fry until crisp and golden-brown all over.
To serve, place three cheese dumplings into each bowl and spoon equal amounts of the casserole around each set of dumplings.