Start by generously seasoning both sides of the roast with salt and pepper.
Next, combine all remaining ingredients ingredients (aside from the olive oil) in a jar and blend with an immersion blender to combine. This will be the sauce that the meat cooks in.
Heat the1 tablespoon of oil in a skillet and sear the roast on both sides. This really helps lock in flavor and prevent the meat from shrinking too much.
Place half of the sauce in the crockpot, add the meat, and pour the remaining sauce on top of the meat.
Cover and cook for 4-6 hours on high or 8-10 hours on low, until the beef shreds easily with a fork.
Serve on a lightly charred tortilla with Pico de gallo and cilantro.