Heat up the cooked beef if using leftovers. We used 3 cups of slow cooker barbacoa, heating it up in a skillet over medium heat in a dollop of oil. For the Pico de Gallo, give the tomatoes, jalapeno and cilantro a good rinse. Peel the onion. Finely chop the 2 tomatoes, 1/2 onion, and single jalapeno into 1/4" sized chunks. Finely dice the cilantro. Combine the tomato, onion, jalapeno and cilantro in a mixing bowl. Add 1/2 teaspoon salt and the juice of a lime. Mix together well and taste for seasoning. Add additional salt and lime if necessary.
For the Guacamole, finely chop 2-3 tablespoons of onion. Use the back of a fork to smoosh the onion until it turns translucent. Add onion to a bowl along with the avocado flesh, 1/8 teaspoon of salt, and the juice of a half lime. Mush together and mix well. Taste for salt level. Keep adding tiny dashes of salt (and lime) until you like it.
If you want to build a batch of Cilantro Lime Rice, please see here. To build the burritos, start by heating up the flour tortillas. I usually heat them up for a couple minutes in the skillet that will be used to cook the burritos.
Each burrito gets rice, beef, Pico de Gallo, and guacamole. (Please see above pic for a good starting point for proportions). Roll tight and saute in a dry skillet over medium heat for 2-3 minutes on each side, or until turning golden brown. Serve immediately.