Heat oil and butter in a large frying pan over medium heat.
Add garlic, chilli, onions, sugar, thyme and basil, and cook, stirring occasionally, for 7 mins or until onions are soft. Set aside to cool.
Meanwhile, preheat oven to 220°C.
Roll pastry between 2 sheets of baking paper to a 20cm x 45cm rectangle.
Remove top sheet of baking paper, then brush a 4cm-thick border around pastry with egg wash. Fold all 4 edges in by 3cm, pressing firmly to seal.
Transfer pastry with baking paper to an oven tray, then brush border with egg wash. Using a fork, prick pastry, avoiding border.
Place in oven and cook for 20 mins or until light brown and crisp.
Scatter caramelised onions, figs, prosciutto, goat's cheese, tomatoes and extra basil to serve.
Servings 4