Begin by making the rice. Stir everything but the salt together in a small saucepan and place over high heat. Bring the liquid to a boil, lower heat and cover. Allow to simmer, covered, until all of the water has been absorbed, about 40 minutes. Remove from heat and allow to sit for 5 minutes with the lid on. Uncover and fluff a few times with a fork. Season with salt to taste.
While the rice cooks, prepare the beans. Coat the bottom of a medium skillet with oil and place it over medium heat. When the oil is hot, add the onion. Cook 5 minutes, until soft and translucent. Add the garlic and cook 1 minute more, until very fragrant. Stir in the beans, cumin, and 1 cup of water. Raise heat and bring the liquid to a simmer. Lower heat and allow to simmer until the beans fall apart completely, about 40 minutes, adding water to the skillet every so often (about ½ cup at a time), as it dries out. When finished cooking, remove from heat and season with salt to taste.
While the beans and rice cook, prepare the tahini cheese sauce by whisking everything together in a small bowl, using as much water as needed to get a nice thick but smooth consistency.
To make the cashew sour cream, place the cashews, lemon juice and ¼ cup of water into blender and blend until smooth. Thin with additional water if you'd like, and season with salt to taste.
To make the guacamole, place the avocado halves into a medium bowl and mash with a fork. Stir in the remaining ingredients and season with salt to taste.
Place a forth of the rice into the center of a tortilla, then place a scoop of beans on top of the rice. Top with tahini cheese, guacamole, cashew sour cream, lettuce, tomato and hot sauce. Roll into a burrito and repeat until all of the tortillas are used. Serve.