Preheat your oven to 325 degrees
Chop onion, peppers, tomatoes, and leek.
Add 3 Tablespoons oil to a large skillet and heat to medium high.
Salt and pepper the short ribs generously and add to the heated pan.
Sear for 2-3 minutes on each side or until a nice crust forms. Remove each short rib from the heat and place in a baking pan. I used a 9" x 12".
In the same pan, add your chopped vegetables and 2 more Tablespoons oil. Stirring often, cook for two minutes.
Add garlic, cumin, chili powder and tomato paste and mix throughout.
Add tequila and beef broth and let come to a simmer cooking for 5 minutes.
Remove from the heat and carefully poor everything over the short ribs.
Cut the orange in half and cut a few thin slices from it. Squeeze the juice from the rest over the short ribs. Place the orange slices on top.
Cover with foil and put in the oven for three hours or until fork tender.
Once it's fork tender remove from the oven. Shred the beef and set aside.
Take all the juices and vegetables (remove the orange slices) and carefully pour into a blender. Pulse until you have a thick sauce. Add at least 1/2 of this mixture to your shredded beef.