Ham and Cheese Croissant Casserole

Ingredients

• 6 stale croissants
• 60 g butter, softened, plus extra for greasing
• 200 g sliced ham, torn
• 100 g mature cheddar, grated
• 100 g Gruyère, grated
• 4 eggs
• 100 ml double cream
• 100 ml whole milk
• 2 tsp Dijon mustard
• 1 tsp thyme leaves
• 10 g chives, chopped
• ¼ tsp ground nutmeg
• 75 g pesto
• 10 g flat-leaf parsley, chopped
• Black pepper
• Fine salt

Method

1. Heat the oven to 180°C (160°C fan). Slice the croissants in half horizontally and butter each cut side generously; stale croissants drink butter where fresh ones would just smear it about.
2. Stuff each croissant with torn ham and most of the cheddar and gruyère, holding back a small handful of each for the custard. Grease a 26cm ovenproof dish and pack the stuffed croissants in snugly; tight enough that they hold each other up.
3. Whisk the eggs with the cream, milk, Dijon, thyme, chives and the reserved cheese until completely smooth and uniform in colour. Season with a good grind of black pepper and a fine grating of nutmeg; go light on salt here, the ham and cheese bring plenty of their own.
4. Pour the custard slowly over the croissants, letting it work its way into every gap. Press the tops down lightly so they drink it up, then leave to soak for 15 minutes; this is what makes the inside silky rather than dry.
5. Spoon the pesto across the top in irregular pools and dot with a little extra butter if you fancy a richer crust. Bake for 30–35 minutes until the tops are deep golden, the cheese is bubbling at the edges and the custard is just set with a faint wobble in the centre; pull it while it still trembles, it firms as it rests.
6. Rest for 10 minutes so the custard settles and the flavours come together.