1.Quarter capsicums, discard seeds and membranes. Roast under grill or in very hot oven, skin-side up, until skin blisters and blackens. Cover capsicum pieces in plastic or paper for 5 minutes; peel away skin, chop coarsely.
2.Meanwhile, cook eggplant and zucchini, in batches, in heated oiled grill pan until tender.
3.Heat oil in large saucepan; cook onion, garlic, thyme and chilli, stirring occasionally, until onion softens.
4.Add capsicum, eggplant, zucchini, sauce and the water; simmer, uncovered, 5 minutes. Remove from heat; stir in basil.