Preheat broiler. Bring a large pot of water to a boil over high heat for the pasta.
Place a medium pot over medium-high heat with 2 turns of the pan of EVOO, about 2 tablespoons. Add the meat to the pan and cook until golden brown, 5-6 minutes.
Add the onion and chili powder to the pan, season with salt and pepper, and cook until the onion is tender, 4-5 minutes. Add the ketchup, mustard and beef stock to the pot, bring up to a bubble and simmer until slightly thickened, 4-5 minutes.
While the chili is working, salt the boiling water and drop the pasta inches Cook to al dente according to package directions then drain thoroughly and return it to the pot.
Add the chili to the pot with the pasta and give everything a good toss. Transfer to a casserole dish and top with the shredded cheese. Place the casserole under the broiler to melt and brown the cheese. Serve with a simple salad alongside.