1.Preheat oven to 180°C. Place onions in a baking tray and drizzle with olive oil. Season. Roast for 20 minutes.
2.Place artichokes in a large pot of cold, salted water. Bring to the boil, then turn off heat and leave in hot water for 10 minutes. Drain and set aside. Once cool, slice into thick chunks.
3.Place sugar in a small, heavy-based saucepan over high heat. Cook until sugar dissolves, then bring to the boil, stirring. Let sugar bubble until it turns a light caramel colour.
4.Pour caramel into a 20cm cast-iron frying pan, lay artichoke pieces over the top (cut-side down), leaving a 2cm gap around the edge.
5.Cut pastry sheet to same size as pan. Lay pastry over artichoke and press edges so they touch the bottom of the pan. Bake for 25 minutes.
6.Serve with roasted red onion, radicchio and hazelnut dressing.
7.To make hazelnut dressing; grind rosemary and salt in a mortar and pestle. Mix with remaining ingredients.
Mike’s Top Tips: – Serving suggestions and kitchen tricks to make this meal your own. If you don’t like artichokes, you can use parsnip, kumara or pumpkin. Skip the boiling and use them raw. Radicchio is a bitter leaf available from specialty shops. The sharp flavour is a great contrast with the tart. Use red endive lettuce if preferred.