1. Peel and roughly chop the onion. Place in the bowl fitted with the ultrablade knife and mix at speed 11 for 10 seconds.
2. Replace the ultrablade knife with the mixer. Add the olive oil, quinoa, tomato purée, water, salt and pepper. Launch the P3 simmer program at 200°F for 20 minutes, with the stopper on.
3. Chop the tomatoes. At the end of cooking, add the tomatoes and gently mix with a spatula. Garnish with the basil leaves and serve immediately.