For the pork: Preheat the oven to 250 degrees F. Portion the pork butt in two equal sections around 1 pound each. Next, in a small bowl, blend the salt, cayenne, black pepper and cumin, mixing well. Then pat dry the pork and rub the exterior with the mixed seasonings. Once rubbed with the seasoning, place in a deep roasting pan. Add the cut vegetables and finish with the stock, then cover with foil. After covering, bake until softened, 2 to 2 1/2 hours. After roasting, remove from the oven, place the pork on a sheet pan and allow cooling. Skim any fat from the stock and reserve. After cooling, pull the meat for burritos, and then place the stock in a saucepot, warming over medium-high heat. Then puree with a stick blender to a create a sauce. Once pureed, taste and re-season if preferred. Then remove from the stovetop and place in a container to cool.
For the rice: Place the stock in a saucepan and warm over high heat. Once hot, add the annatto seed and stir until dissolved. Then remove from the stove and pour over the raw rice in a 2-inch deep baking pan. Add the cilantro and jalapenos, cover with foil and place in the oven until cooked, about 30 minutes. All liquids should be absorbed for the rice to be cooked.
For the burritos: To build the burritos, in a large saucepan over medium-high heat, add the pork and 1 cup reserved puree, stirring while warming for 4 to 5 minutes. Then add the cilantro, salt, pepper and lemon juice and warm. Then reduce the heat to low and keep the pork hot. Next, lay a tortilla flat and add in the center section 1 cup warmed pork, 1/4 cup rice, 2 tablespoons beans and 1 tablespoon cheese. Fold the bottom edge of the tortilla to meet, and then pull the sides over covering one another. Next, in a separate pan or on griddle, add 1 teaspoon reserved pork fat and heat over medium heat and allow to warm. Add the burrito and sear on the first side until crisp, 2 to 3 minutes, and then repeat on the second side until browned. Repeat the process with the remaining tortillas and filling.