Preheat oven to 180C / Fan 160C. Grease a loaf tin with a little butter, and line with greaseproof paper. 

Finely chop onion and mushrooms. Crush garlic. Grate carrot on the coarse side of a cheese grater.

Heat some vegetable oil in a large pan. Add finely chopped onion, crushed garlic. Fry gently until soft. Add grated carrot, mushrooms, water and tomato paste. Stir until mixed and cook covered under medium heat for 10 minutes. Remove lid and cook for another 10 minutes until liquid has evaporated.

Rinse and drain lentils and cannellini beans. Mash together with a potato masher. Add cooked vegetable mixture, dry herbs, mustard, porridge oats, grated cheddar cheese, cranberries and beaten eggs. Mix well together until blended.

Pour mixture in prepared tin, spreading the top evenly. Cook for around 40-45 mins. When done, leave to cool in the tin for around 15 mins then flip over carefully onto a serving dish. Serve with your favourite chutney and/or gravy. 

You can prepare a day ahead and keep it in the fridge wrapped overnight. Slice the lentil roast cold and reheat on plates in the microwave just before serving.