Heat oil in a large, nonstick skillet set over medium-high heat. Crumble in ground beef; season with chili powder blend. Cook, stirring and breaking up beef, for 5 to 7 minutes or until browned.
Rinse with hot water and drain.
Stir in onion and pepper. Cook, stirring occasionally, for 3 to 5 minutes.
Reduce heat to medium-low. Pour in soup and broth; bring to a simmer. Cook, stirring often, for 5 to 7 minutes or until sauce is thickened. Remove from heat.
Fill taco shells with shredded lettuce and some of the beef mixture. Garnish with Cheddar, sour cream, tomatoes and green onion.
Notes
You can also make soft shelled using the same process.