Fill a large heavy-bottomed pot with 5 quarts water and bring to a boil over high heat. Add the bouillon cube and stir to dissolve. Add the pasta and cook until al dente according to the package instructions. Drain the pasta and slide to the side.

Position a rack in the middle of the oven and preheat to 375°F.

In a large bowl, toss together the cheddars, Colby Jack, Gruyère, and mozzarella until combined.

In a large heavy-bottomed pot, melt the butter over medium heat. Whisk in the flour and cook, whisking continuously, to form a roux, about 1 minute. Whisk in the garlic powder, onion powder, salt, black pepper, paprika, mustard powder, sugar, nutmeg, and cayenne until incorporated. Whisk in the heavy cream, milk, sour cream, Worcestershire, and hot sauce until combined and let the sour cream completely melt into the sauce. Whisk in half the shredded cheese mixture and let it melt completely into creamy deliciousness, whisking all the while. Whisk until the sauce thickens a bit, about 3 minutes, then add the drained pasta and stir to evenly coat it in the sauce.

Transfer a third of the pasta mixture to a 9 by 13 by 2-inch baking pan and top with a third of the remaining cheese mixture, then repeat two more times, finishing with the cheese. Bake for 40 to 45 minutes, until the pasta is golden brown in places and the sauce is bubbling. Remove from the oven and let cool for 10 minutes, then garnish with chives and serve hot. May the cheese pulls be ever in your favor.