Finely dice the yellow onion, mince the garlic, and slice the cremini mushrooms.
Heat the olive oil in a large skillet over medium-high heat.
Add the ground beef to the skillet, breaking it up with a spatula, and cook until browned.
Stir in the onions and mushrooms, cooking for 5-7 minutes until the mushrooms have released their moisture and the onions are translucent.
Add the minced garlic, sea salt, black pepper, and dried thyme, sautéing for another 60 seconds until fragrant.
Fold in the baby spinach and cook just until wilted.
In a small dry pan over medium heat, toast the almond flour and nutritional yeast for 1-2 minutes until golden and fragrant.
Transfer the beef and mushroom mixture to a bowl and sprinkle the toasted almond crumble over the top before serving.