Add ground beef to heavy pan (preferably NOT a non-stick pan) over medium high heat and begin browning. If you are starting with frozen meat, put a lid on your pan and it will cook much faster.
Meanwhile, chop the onion and add to pan.
Continue to stir meat and onion until cooked, but not browned. Season with a little salt.
While meat and onions are cooking, slice mushrooms and mince garlic and then add to the skillet. Continue to brown this mixture until it is nicely browned and you develop some of those good bits on the bottom of the skillet (that brown stuff is called fond and it adds a lot of flavor to your dish). See all that brown stuff in the picture? You want that. It's not burned. I promise.
Add arrowroot or cassava (I prefer arrowroot, but either will work) and stir until well distributed.
Slowly add broth, stirring and scraping the fond off the skillet. Use a wooden spoon or metal spatula for this. Add coconut aminos now as well.
Cook this mixture for 2-3 minutes. While that is cooking away, collect the cream from your coconut milk can and mix with the lemon juice (store the liquid in a sealed container in the fridge for a future use). This is your sour cream substitute.
Add the coconut/lemon juice mixture to the skillet right before serving. Stir well and make sure it is heated through and seasoned to your liking. Add a little more salt and/or pepper if desired.
Serve over rice, zucchini noodles, gluten free pasta or mashed cauliflower.