1. Line a greased 20 cm (8 in) flan tin with puff pastry and prick base with a fork. Line with baking paper and fill with uncooked rice. Bake for 10 minutes then remove rice and paper and bake for 5 minutes longer. Spread pastry with mustard, and sprinkle with spring onions, basil and cheese.
2. Arrange tomatoes over cheese and season to taste with black pepper. Bake for 10 minutes or until cheese melts.