2 tbsp. melted butter
2 or 3 tbsp. flour
3/4 c. milk or more (so it doesn't thicken)
1/2 tsp. salt
1/2 c. or less chopped cheese

Melt butter, add flour. Add milk and salt. Add cheese and let cook. Cook cauliflower, salt it. Pour on sauce. Put some cheese on top and put in oven for 5 minutes to melt.