In a large pot, bring water to a boil and add cauliflower florets. Cook for about 5 minutes until tender but not mushy. Drain and set aside.
In the same pot, melt butter over medium heat. Once melted, whisk in flour, stirring continuously for about 1 minute.
Gradually add milk while whisking until the mixture is smooth and thick. Stir in cheddar cheese, mustard powder, salt, and pepper until cheese has melted.
Combine the cooked cauliflower with the cheese sauce and pour into a greased baking dish.
In a bowl, mix breadcrumbs with olive oil. Sprinkle over the top of the cauliflower and cheese mixture.
Bake in the preheated oven for 25-30 minutes until the top is golden brown and crispy.
Remove from the oven and let it cool slightly before serving.
Notes
For a creamier texture, add an extra splash of milk to the cheese sauce. You can also mix in some cooked broccoli for added nutrients and flavor.Feel free to switch out the cheese; cheddar and Gruyère create a fantastic flavor combination!To make this dish a bit healthier, use whole wheat breadcrumbs or sprinkle some nuts on top for added crunch.