Season the flank steak generously with salt and pepper. Set aside.
Heat olive oil in a large skillet over medium-high heat. Sear the flank steak for 2-3 minutes on each side until browned. Remove from the skillet and transfer it to a plate.
Add red wine to the skillet and deglaze the pan, scraping up any browned bits.
Transfer the contents of the skillet to the crockpot.
Add the seared flank steak, beef consomme, San Marzano tomatoes, sliced green and red bell peppers, onions, minced garlic, bay leaves, cumin, paprika, and oregano to the crockpot. Gently squeeze the tomatoes to release their juices.
Cover the crockpot with the lid and cook on low heat for 6 hours, or until the flank steak is tender and easily shreds apart.
Once the cooking time is complete, remove the flank steak from the crockpot and shred it using two forks. Discard the bay leaves.
Use a stick blender to blend the sauce in the crockpot until smooth. (See notes below to create a thicker sauce).
Return the shredded flank steak to the sauce in the crockpot and add Spanish olives. Stir everything together to combine.
Allow the mixture to heat through for an additional 15-20 minutes on low heat.
Serve the delicious flank steak stew over rice and beans, and garnish with fresh cilantro, if desired.