Have the lentils and all the vegetables well washed (in cold water) and prepared as indicated in the ingredients description.
Heat the olive oil in a large saucepan. Add the carrots and cook over a low heat, stirring frequently, for about 2 minutes. Add the onion and a pinch of salt and stir-fry for 2 more minutes until only lightly golden. Add then the red bell pepper, the potato and the garlic clove stir-fry over medium heat for around 2 minutes until soft but not brown.
Reduce heat to low. Add the tomatoes, the bay leaf, the lentils and stir. Cover with cold water and leave to cook, covered with a lid, at a medium-low heat for approximately 20 minutes, or until the lentils are “al dente”, stirring from time to time. Add a teaspoon salt (or salt to taste) and stir.