Heat the avocado oil in a large cast-iron skillet over medium-high heat until shimmering.
Add the ground beef to the skillet, seasoning immediately with the sea salt, black pepper, and garlic powder.
Cook the beef for 6-8 minutes, using a spatula to break it into small crumbles, until it is fully cooked and the edges are browned and crispy.
While the beef is searing, wash and chop the romaine lettuce into bite-sized pieces and place them in a large bowl.
Slice the cherry tomatoes in half, finely dice the red onion, and chop the dill pickles into small rounds or chunks.
In a small ramekin, mash the avocado with a tiny pinch of sea salt until smooth and creamy.
Top the bed of romaine with the hot crispy beef crumbles, followed by the tomatoes, onions, and pickles.
Finish the bowl with a dollop of mashed avocado and a generous drizzle of yellow mustard before serving.