Preheat your oven broiler to high and set the rack to the upper-middle position.
Finely chop the cremini mushrooms and small-dice the yellow onion to ensure they integrate well with the beef.
In a large oven-safe skillet, heat 0.5 tbsp of olive oil over medium-high heat.
Add the ground beef, sea salt, and black pepper to the skillet, breaking the meat into small crumbles with a wooden spoon until browned and cooked through.
Stir in the diced onions and chopped mushrooms, cooking for 5 to 6 minutes until the vegetables are soft and the liquid they released has mostly evaporated.
Add the minced garlic, beef bone broth, and coconut aminos to the skillet, simmering for 2 minutes until the liquid is slightly reduced but the mixture remains very moist.
In a small mixing bowl, whisk together the almond flour, dried thyme, and the remaining 0.5 tbsp of olive oil until a sandy, clumped crumble forms.
Sprinkle the almond crumble evenly over the top of the beef and mushroom mixture in the skillet.
Place the skillet under the broiler for 2 to 3 minutes, watching closely, until the almond topping is fragrant and turns a light golden brown.