Add the olive oil to a large Dutch oven over medium-high heat. Once hot, add the onions and peppers and saute until soft, about 4 minutes. Add the garlic and saute until just fragrant. Stir in the beef and sausage, breaking it up with the back of a wooden spoon, and cook until browned.
Drain the beef mixture through a colander placed over a large bowl. Add the meat back to the Dutch oven and stir in the chili powder, cumin and oregano. Cook for about 2 minutes. Stir in the tomato paste into the beef; this will "toast" it and give the chili more flavor. Add the beer and stir up any browned bits on the bottom of the pan. Bring to a simmer, and then add the diced tomatoes and beans. Simmer on medium-low for 2 hours, stirring on occasion to keep the bottom from sticking.
Top with shredded cheese, sour cream and chopped green onions before serving.
This recipe has been updated and may differ from what was originally published or broadcast.