Melt the coconut oil in a medium skillet over medium heat. Once the coconut oil has melted, add the onion and sauté until soft. Add the garlic and sauté until fragrant, about 30 seconds. Add the meat and cook until no longer pink. Add the taco seasoning to the meat and mix well.
While the meat is cooking, make the simple dressing. Place the oil, egg, mustard powder, lemon juice, lime juice, garlic and salt in a tall container. (I use a 2 cup Pyrex measuring cup). Place an immersion blender at the bottom and turn on. Once the mixture starts to blend together and become thick, move the immersion blender towards the top, until it is well blended. This should take less than a minute! Stir in the cilantro. [Steph’s note: No immersion blender? Place the egg, mustard powder, lemon juice, lime juice, garlic and salt into a blender and let these come to room temperature. Run the blender for about 30 seconds, then with the blender on medium speed, very slowly (in a thin stream) drizzle in the avocado oil until the mayo has thickened.]