• Heat the oil in a large skillet, and brown the roast on all sides. Note: You can skip this step if you'd like.
• Chop the garlic. In a small bowl, whisk together the garlic, cumin, oregano, broth, lime juice, salt and pepper. Add in 2 to 3 tbsp. of diced chipotle peppers (or substitute 2 tbsp. chipotle in adobo, but check the label!).
• Transfer the beef to your crockpot. Pour the chipotle and broth mixture into the slow cooker over the roast. 
• Cover the slow cooker and set it to low. Cook for 6 hours, until the beef is fall-apart tender. 
• Meanwhile, slice the bell peppers and onions. Using the same skillet you browned the beef in, sauté the vegetables over medium heat in 1 tbsp of oil, for about 7-9 minutes, stirring occasionally. Set it aside.
• Tear or chop the romaine for salads.
• Saute the cauliflower rice in a large skillet over medium heat, stirring occasionally, for about 10 minutes.
• Once it's cooked and very tender, remove the beef from the slow cooker and set it in a large bowl. Using two forks, shred the beef, setting aside any tough fatty pieces.
• Return the shredded meat to the slow cooker, cover, and set it to "Keep Warm," for at least 15 minutes or until you're ready to eat.

Assemble and Serve

• Cut the avocados just before you're ready to eat. Divide the romaine among four bowls. Top each bowl with the beef, cauliflower rice, avocado, pico, cilantro and lime slices.