In a medium bowl, whisk together all the ingredients for the sauce and set aside.
Bring a large pot of water to a boil and cook the pasta according to the directions on the package.
In a large skillet over medium-high heat, heat up the vegetable oil. Add the onion, green bell pepper and garlic. Sauté until fragrant and softened, about 5 minutes.
Add the ground beef to the skillet and break it up with your spatula or wooden spoon. Cook until ground beef is thoroughly cooked through, about 5 to 7 minutes.
Add the sauce to the skillet, then add the pasta (drained of excess water). Add the cheese on top. Turn the heat down to medium-low and toss the mixture until the cheese has melted and the ingredients are evenly coated and distributed throughout. Serve warm.