Had doubts about the mustard but it was fine. Just add salt and pepper to taste to give it more flavor. I overcooked my penne on accident because I had forgotten to cut my broccoli into smaller pieces before starting to boil the pasta and it took me longer than I thought with a fussy baby bugging me. I also added a splash of milk to the bottom of my baking dish before broiling to crisp up the top and melt everything together. To ensure good mixing, add the pasta, then cheese sauce, then pasta, then cheese sauce, etc. and mix in between each addition. Also ran out of cheddar but had gruyere from another recipe I shredded and used along with the cheddar I had. Very easy recipe to tweak to your likings.
