Boil the farro according to package instructions, drain and set aside.
Heat the oven to 350 degrees F. Use the 1 tsp butter to butter a 9 x 13 casserole dish.
In a sauce pot melt the 4 TBSP butter over medium heat and whisk in the flour. Continue to whisk until the mixture smells faintly of toasted nuts.
Add the milk, salt, pepper, hot sauce, and nutmeg and stir until the milk is thickened, about 5 minutes, do not boil.
Take off the heat and stir in the cheese.
In a large bowl add the farro and cauliflower and toss together. Pour the cheese sauce over and stir to coat.
Pour the mixture into the buttered casserole dish. Cover with foil and bake for 20 minutes.
Increase the oven to 425 degrees F. Uncover and sprinkle with panko and paprika and bake uncovered for 10 more minutes.
