Dinner Tonight: Penne with Tuna and Spicy Mustard

It's often said that a work of great design is complete only when there's nothing to add, and nothing to take away. Without taking cooking too seriously, I'd say this is true of recipes as well.
More often than not, a great dish will either surprise you with an unexpected addition, or more often, by removing what doesn't need to be there. Sometimes it's both. And that's true of this gem from Patricia Wells' recent book Salad as a Meal.
I've had and enjoyed recipes with pasta and tuna before, including, of course, the famous Tuna Casserole. But this recipe is my favorite of all of them. Wells uses the oil from the tuna (making it essential to buy good-quality stuff packed in olive oil) mixed with spicy whole-grain mustard. She calls for Piment d'Espelette mustard, though a whole-grained mustard will suit just fine.

Either way, it sort of melts into the dish leaving behind tiny orbs of spiciness that cling to the noodles. It's the best three-ingredient dish I've eaten in a long time, though I did cheat and add a little chopped parsley. If only for the picture.