1.Preheat oven to 200°C.
2.Heat half the oil in a large frying pan over medium-high heat; cook onion, stirring, for 15 minutes or until onion caramelises. Add rosemary; cook, stirring, for 1 minute or until fragrant.
3.Whisk eggs, milk and half the cheese in a large jug. Combine onion, ham and almonds in a medium bowl. Layer bread and ham mixture among four 2 cup (500ml) ovenproof dishes. Pour over egg mixture; sprinkle with remaining cheese. Stand for 20 minutes.
4.Bake for 35 minutes or until just set, golden and puffed.
5.Meanwhile, cut tomatoes into four clusters; place on an oven tray, drizzle with remaining oil. Roast for the last 10 minutes of strata cooking time or until skins start to split.
6.Serve strata topped with tomatoes and basil.
Serve with a mixed garden salad.Note