In a heavy skillet set over medium high heat melt a little bit of cooking fat (lard, ghee or coconut oil preferred). When fat is nice and hot, add onions, garlic, salt and pepper and cook until the veggies are fragrant and softened, about 2-3 minutes.
Add ground beef, chili pepper, cinnamon and allspice and continue cooking until the beef is no longer pink.
Stir in the Dijon mustard and coconut aminos, then add the plantain and continue cooking until it becomes really soft and only a few visible pieces remain. It might help to smoosh it with your spoon to better break it down.
Add squash puree and water and continue cooking until well combined, creamy and heated through.