Heat a large high-sided skillet or Dutch oven over medium-high heat. When hot add oil (optional), swirl to coat.
Add the beef into the pot, making sure you don't crowd the pan. We want the beef to sear on two sides to a nice golden brown, and if you crowd the pan it will steam. Let the first side sear, flip to the second side only when a golden brown crust has formed. Sear the beef in multiple batches if you need to, just add everything back into the pot when it's all seared.
Once all of the beef is seared, pour in your jar of Mesa de Vida Latin Cooking and Seasoning Sauce.
Add salt and hot sauce to taste, optional. Stir everything to combine. Simmer for about 30 seconds.
Break up the piece of dark chocolate, if using and stir in.
*Prefer to make this in your slow cooker? At this point you can transfer everything to the slow cooker, cover and cook on low for 4-6 hours.
Lower the heat to low, cover, and simmer for 40-50 minutes, until your beef is fall-apart tender.
Serve and enjoy!