Party Taco Salad

1 lb. lean ground beef
½ cup chopped green pepper
1 cup chopped onion
1 T chili powder
1 ½ lbs. iceberg lettuce, shredded
2 large tomatoes, chopped
1 (10.5 oz) package corn chips
1 (16 oz) loaf Velveta, cut into pieces
1 (10 oz) can diced tomatoes and green chiles

Cook first 4 ingredients in a large nonstick skillet over medium heat until beef is done, stirring to crumble beef; drain.
Place shredded lettuce in a large bowl; top with chopped tomato, corn chips, and beef mixture.
Combine cheese spread and diced tomatoes in a saucepan, cook over low heat, stirring often, until cheese melts.  Pour cheese sauce over salad, and serve immediately.