Place lentils in a large saucepan with enough cold water to cover generously.

Add onion, carrots & celery (if using), and bring to the boil.

Turn the heat down to medium high and simmer rapidly for 15-20 minutes or until the lentils are cooked. I like them al dente like pasta but its up to you. If the lentils look dry add more water.

Drain the lentils well and place in a mixing bowl or back into the saucepan.

Stir in 3 tablespoons extra virgin olive oil. Season with soy sauce, vinegar, and a little salt and pepper if you like.