Heat the oil in a large non-stick frying pan. Add the onion and sauté for a couple of minutes, add the pepper, aubergine cubes, a few basil leaves and cook for 6 minutes, stirring occasionally. Season with salt and pepper to taste, sprinkle with sugar, add vinegar and cook for 2 more minutes to combine.
Cook the tortelloni for 2 minutes in a large pot of salted boiling water.
Strain delicately with a skimmer and add to the sauté pan along with 2 tbsp of pasta cooking water. Toss gently to combine and divide between 2 plates. Garnish with basil leaves and serve.