Prepare all of the ingredients and pre-heat the oven to 180c.
Heat the oil on a medium heat in a pan then add the onion, carrot, courgette and pepper. Stir and cook until golden.
Add the garlic, lentils, can of tomatoes and fill the can with water then add that to the pan.
Bring to the boil then turn down to a simmer cooking for 10-15 mins until the lentils soften. Remove from the heat then blend.
Add both types of potatoes, drained butter beans and chopped bacon to the pan with the sauce, stir then layer in a lightly oiled roasting pan.
Bake for 40-60 mins until the potatoes have softened. If it starts to brown too much, cover with foil halfway through.
Serve on it’s own or with a side salad.