In a small bowl, combine tomatoes, white onion. cilantro, diced jalapenos, lime juice and salt to make quick pico. Stir to combine, cover and place in refrigerator until ready to build tacos.
In a mixing bowl, combine beef broth, tomato paste and taco seasoning.
In a large saute pan over medium high heat, add ground beef. Cook and crumble until no longer pink. Reduce heat to medium and add broth mixture. Let simmer (stirring occasionally for 30 minutes).
In a small frying pan or grill pan over medium high heat, lightly toast each tortillas (about one minute on each side).
Smear half of tortilla with sour cream. Sprinkle with cheese. Add portion of ground beef. Top with shredded lettuce and spoonful of pico. And a slice of jalapeno, if desired.