Wash the vegetables and dry. Cut the green peppers in half, remove the seeds, and cut into bite-sized chunks. Peel and chop the onion. Smash, peel, and chop the garlic cloves. If using the jalapeños, slice lengthwise, remove the seeds, and coarsely chop.
Heat the vegetable oil on medium-high in a large, heavy saucepan. Add ½ of the beef cubes and brown. Remove the beef cubes from the saucepan and drain on paper towels. Repeat with the remaining beef.
Add the green peppers, onion, garlic, and chili peppers to the saucepan. Cook on medium heat until the onion is tender. Add the tomato sauce, tomato paste, and sugar. Stir in the chili powder, oregano, salt, and pepper.
Bring the chili to a boil. Reduce heat to medium-low, cover, and simmer for 90 minutes or until the beef is tender. Add about 1 cup water to the chili to adjust consistency if desired. Serve with the tortilla chips.
Chili Pepper Safety
The same oil that gives chili peppers their fiery heat can cause serious damage if it gets in the eyes. Always wear plastic gloves when handling chili peppers. Be sure to wash your hands in soapy water immediately afterward.
Want to serve guests something a little more economical? Ground beef can be substituted for the boneless beef cubes. If using ground beef, reduce the amount of vegetable oil to 2 tablespoons.