Mix together into a paste - Smoked Paprika, Oregano, Cumin, Salt & Pepper, Cinnamon, Lemon Zest & Juice.
Place the browned Beef in Slow Cooker and rub half of the spice rub on one side and then turn and rub the remaining spices to the other side.
Add on top of meat the Chopped Peppers, Chilli (optional), Tomatoes and Water, 1/2 bunch of chopped Cilantro and Chocolate.
Stir to mix.
Turn on to High & cook for 1 hour.
Turn down to Low and continue to cook for 8 - 10 hours, stirring around occasionally and if it looks dry then add 1/2 cup water, but only if needed.
Taste and adjust seasonings if needed.