1. Peel and roughly chop the onion. Place in the bowl fitted with the ultrablade knife and mix at speed 11 for 20 seconds.
2. Replace the ultrablade knife with the mixer, scrape down the sides of the bowl and add the oil and coriander. Start the P1 simmer program at 270°F for 5 minutes.
3. Cut large mushrooms into quarters. Dice the tomatoes and remove seeds. At the end of the program, add the mushrooms, thyme, white wine, lemon juice, tomatoes and sugar. Season with salt. Launch the P2 simmer program at 210°F for 30 minutes.
4. Cool. Cover and refrigerate before serving.