Heat oil in a large sauce pan over a medium high heat. Add the onions, garlic and carrots, reduced the heat, and sauté for 5 mins.
Add the red split lentils and sweet potato and stir for a further 5 mins.
Add the water, cover and simmer on a low heat for approx. 30 mins. (making sure to check and stir mixture so it does not burn) SEE NOTE 2
Mash together and chill for 30 mins.
Pre heat oven to 190c / 375f / gas 5
Add egg, cheese and coriander to the sweet potato and lentil mixture. Stir to combine. SEE NOTE 3
Use a heaped tablespoon of mixture to form each croquette and roll them into small sausage like shapes. It is easer if you form rough croquette shapes first, until all the mixture is used, them wash your hands and roll the croquettes in the breadcrumbs. You can tidy up the shape, while rolling in the breadcrumbs, until they look like the croquettes pictured.
Place on a greased baking tray, lightly spray with oil and cook for approx. 30 mins (until golden)