Increase heat to medium-low and cook until garlic and shallots are translucent, about 3 minutes more. Meanwhile, bring a large pot of salted water to a boil over high heat. Add pasta and cook 2 ...

While the pasta is cooking, bring the Onion-Garlic Puree, mustard, and cayenne to a simmer in a small saucepan over medium heat, stirring often. Whisk in the cheddar until it has melted.