Get pickling! This can be done anytime ahead, even days before to save time. Place sliced onion in a medium container or bowl. Bring the remaining pickling ingredients to a boil and pour over raw red onions, cover, transfer to the fridge and allow to sit for at least 2 hours.
Prepare the seasoned beans. Heat oil over medium heat, add beans, cook for 2 minutes, add seasonings, cook for another 2 minutes, turn off heat and deglaze the pan with the water.
Make avocado crema. Blend all crema ingredients together in a blender or food processor until creamy and smooth.
Heat tortillas in a low frying pan or wrap in a paper towel and microwave until soft and warm. Assemble tacos with whole grain tortillas, or corn tortillas for a gluten free option.
Garnish tacos with chopped cilantro, goat cheese, pickles and crema. Enjoy!