In a small bowl, combine the oil, Tabasco, and Worcester sauce. Add the meat slices and mix until coated. Refrigerate for at least 10 minutes.
Wash the bell peppers. Cut each pepper lengthwise into 6 pieces. Remove the seeds and white membranes. Cut the pepper pieces crosswise into narrow strips.
Heat a large pan over medium-high heat without adding oil. Add the meat and its marinade, then the diced onion. Fry for 5 minutes, stirring occasionally.
Add the bell pepper strips and fry for 2-3 minutes.
Mix the salsa with 2 tablespoons of water, then add to the pan. Heat through for about 1-2 minutes.