Step 1) Combine oil, vinegar, chipotle chilies, bouillon powder, garlic, oregano and brown sugar in a electric blender or food processor. Puree until smooth.
Step 2) Place steak in a large resealable plastic bag, pour the marinade over the steak, seal and turn to coat thoroughly. Marinate for 15 minutes turning occasionally.
Step 3) Coat grill surface with grill spray to prevent sticking. Preheat grill to medium high heat or about 400°F.
Step 4) Remove steak from marinade and place on grill; discard remaining marinade. Grill for 6 to 8 minutes, turning once, or to desired doneness. Transfer steak to a cutting board and allow to rest for 5 minutes. Thinly slice steak across the grain.
To assemble the Torta: Place bread halves onto a large cutting board or sheet pan. Spread a thin coating of the Spicy Chipotle Ranch dressing on the inner surface of each bread half. Line the bottom half with the steak slices. Arrange a single layer of each desired topping ingredient on top of the steak ending with the top half of the bread. Firmly press sandwich together and slice across width into individual servings.
To make Spicy Chipotle Ranch Salad Dressing, combine all ingredients in a blender or food processor. Puree for 1 minute until very smooth, scraping down sides as needed. Serve immediately or cover and store refrigerated for up to 1 week.