Break the broccoli and cauliflower into florets and boil or steam for about 5-10 minutes. Leave to drain then arrange the florets in a casserole dish.
Melt the butter in a saucepan until foaming then tip in the flour and stir constantly for 1 minute.
Remove the pan from the heat and slowly add half of the milk, stirring to combine.
Return the pan to the heat and stir in the remaining milk. Stir constantly and bring to the boil.
Turn the heat down to a simmer and cook stirring for a further couple of minutes.
Stir in most of the cheese then turn off the heat and stir until the cheese has completely melted.
Stir in two thirds of the chives black pepper and nutmeg and check the seasoning.
Pour the sauce over the florets and top with the remaining cheese and chives.
Bake in the oven at 200C/180 FAN/400F/Gas6 for about 10 minutes or under a hot grill if you like the cheese crispy.
Notes
Disclaimer:The nutritional information provided is approximate and is calculated using online tools. Information can vary depending on various factors, but we have endeavoured to be as accurate as possible.Top tips:
when you are boiling the vegetables be sure to let them drain properly or else water will leech into the sauce
if you are worried about any lumps developing in the sauce, remove from the heat immediately and beat the sauce vigorously with a wooden spoon or even a balloon whisk
don't be tempted to add salt to the sauce before the cheese as cheddar is naturally quite salty