Bring large pot of water to a boil over medium heat. Salt water and add broccoli and cauliflower florets. Boil vegetables for 5 minutes, then remove with a spider or a strainer and drain.

Add pasta to water and undercook by about 2 minutes, drain.

Meanwhile, combine sour cream in large bowl along with mustard, chives, garlic, hot sauce, salt and pepper, to,taste.

Add pasta and cauliflower and broccoli and 2/3 of the cheese. Stir to combine, them transfer to a casserole dish and cover with remaining cheese. Cool and chill for a make-ahead meal.

To heat and eat, put casserole on baking sheet and bake in the middle of a preheated 375°F ovenmuntil deeply golden and bubbly, about 40 to 45 minutes.

Tip: Make a double batch and freeze for a later date.