Heat 1 tablespoon of the oil in a large nonstick skillet over medium high; add the onion and garlic and cook, stirring occasionally, until somewhat softened, about 3 minutes. Add the beef, crumbling it with your spoon; stir in the chili powder, cumin, oregano and salt and cook, stirring, until the beef is no longer pink, about 3-4 minutes. Stir in the tomatoes and tomato paste and simmer 5 minutes.