In a large stock pot (with a lid), add the flank steak and fill with water about ¾ full. If you would prefer to use a slow cooker, see notes above.
1 Flank Steak, water
Next, cut off the tops of the red and green peppers and throw those in to the stock pot. Reserve the remaining parts of the peppers for later.
1 large red pepper, 1 large green pepper
Next, cut off about ¼ of the onion and throw that into the stock pot as well. Remember to reserve the remaining peppers and onion for later. Don't worry about the stems and skin as that will all be discarded later.
1 large spanish onion
Add the bay leaf, black peppercorns and 1 teaspoon of the cumin to the stock pot and cover.
1 bay leaf, 1 teaspoon black peppercorns, 2 teaspoon cumin (divided)
Bring to a boil and then reduce to low to keep a steady simmer going but not boiling over. Cook for about 3-4 hours until testing the meat shows it will fall apart easily.
You may need to top off your pot with more water if too much of the cooking liquid evaporates during cooking.
Once the meat is ready (easy to pull apart) take it out of the pot and place it on a plate to rest.
Scoop up 3 cups or so of the water that the meat cooked in and set aside for later (I use my large measuring cup). You can now discard the rest of the water in the stock pot.
After the meat has cooled, begin shredding it by using 2 forks to create strings with the meat.
After that is done, get out the peppers and onion from earlier and thinly slice them along with the garlic.
2 cloves of garlic
With a deep saute pan, saute the peppers, onion and garlic for about 3-4 minutes and add a pinch of salt to get them to release their juices.
Next add the can of diced tomatoes and the remaining 1 teaspoon of cumin and stir together.
1 14 oz can diced tomatoes, 2 teaspoon cumin (divided)
Add the shredded meat to the pan along with about 1 cup of the cooking liquid (or more if needed to surround the meat well with the broth). Mix well so that the meat is sitting in all of the yummy broth.
Let this simmer on low heat for about 30 minutes.
Season with salt and pepper to taste and serve over a bed of rice that will soak up all of the yummy juices.
1 teaspoon kosher salt, ½ teaspoon fresh black pepper