Heat the olive oil in a large pot over medium heat. Add the diced onion and ground beef, cooking until the beef is no longer pink and the onions are translucent, about 5-7 minutes.
Drain any excess fat from the pot. Add the minced garlic and sauté for an additional minute until fragrant.
Stir in the diced tomatoes (both regular and with green chiles), red kidney beans, and all the seasonings: salt, pepper, chili powder, cumin, paprika, and oregano. Mix thoroughly to combine all the ingredients.
Bring the mixture to a boil, then reduce the heat to low. Cover the pot and let it simmer for approximately 20 minutes, stirring occasionally to prevent sticking.
Taste and adjust the seasonings as needed before serving.
For an extra flavorful touch, consider topping your beef chili with green onions, shredded cheese, sour cream, or fresh herbs.
This dish can be stored in an airtight container in the fridge for up to 4 days or frozen for up to 4 months, making it a perfect make-ahead meal. Enjoy it with cornbread for a complete and satisfying dinner!