Cook pasta according to packet instructions. Drain.

Meanwhile, heat a little olive oil in a large non-stick frying pan over medium heat. Add onion and garlic and cook, stirring, for 5 minutes or until softened. Add mushroom and cook, stirring, for 5 minutes or until golden.

Add tomatoes, lentils, balsamic and 80ml water to pan. Bring to the boil, then reduce heat to low and simmer for 10 minutes or until thick. Season with freshly ground black pepper. Toss pasta in lentil mixture, then serve sprinkled with baby rocket.