300g broccoli, chopped into florets
350g cauliflower, chopped into florets
220g Brussels sprouts, quartered
1 tsp olive oil
2 onions, sliced
Salt and black pepper
60g plain flour
250ml milk, at room temperature
120ml Irish Yogurts Clonakilty Half Fat Crème Fraîche
½ tbsp Dijon mustard
120g Gruyère, grated
120g Gouda, grated
For the topping:
- Preheat the oven to 180˚C/160˚C fan/gas mark 4.
- Bring a large pot of water to the boil. Add the broccoli, cauliflower and Brussels sprouts and cook for 2-3 minutes until the broccoli turns vibrantly green.
- Transfer the vegetables to a large bowl of iced water for two minutes, then drain and place in a large casserole dish.
- Heat the olive oil in a saucepan over a medium-high heat and cook the onions for 4-5 minutes until golden and soft, stirring occasionally. Season with salt and black pepper.
- Reduce the heat to medium-low heat and add the butter. Once melted, gradually mix in the flour, whisking constantly. Continue cooking and whisking for 1-2 minutes.
- Gradually add the milk, whisking constantly until smooth. Stir in the Irish Yogurts Clonakilty Half Fat Crème Fraîche and whisk for two minutes until completely smooth.
- Remove the saucepan from the heat and stir in the mustard, half of each of the cheeses and some salt and black pepper to taste.
- Pour the sauce over the vegetables, then top with the remaining cheese.
- Melt the butter for the topping in a microwave-safe bowl, then stir in the breadcrumbs until combined. Sprinkle over the top of the gratin.
- Bake for 20-25 minutes until golden on top and bubbling around the edges.
Love your leftovers
This gratin will reheat well if you have some left after Christmas dinner: it’s ideal for lunch, with some good bread. Meat-eaters may also enjoy it with some leftover ham.
You can have the gratin made a day ahead. Store overnight in the fridge and simply pop in the oven on Christmas Day.