Step 1

Heat the olive oil in a saucepan over medium heat. Add the onion, carrot and celery and cook, stirring, over low heat for 5 minutes until softened.

Step 2

Add the garlic, cumin, tomato paste, tomatoes and 1/2 cup water. Bring to the boil and season with salt and black pepper. Turn the heat to low, simmer for 10 minutes, add the lentils and cook for a further 5 minutes.

Step 3

Meanwhile, cook the spaghetti in boiling, salted water according to packet instructions. Drain and toss with sauce.

Step 4

Divide between serving bowls and sprinkle with feta.