Melt the butter in a pot over low heat. Add minced garlic, ground raw ginger, onion powder, and black pepper to the butter. Place a lid over the pot and let the melted butter bubble with the spices until they become fragrant. Let the butter cook with the spices for an additional 1-2 minutes until the butter turns a little darker and the garlic and ginger may turn a little golden.
Stir soy sauce, beef broth, and liquid stevia into the butter. Put a lid back on the pot and bring the liquid to a boil. Once the sauce hits boiling, reduce the heat to a simmer and let it simmer covered for 3-4 minutes. Watch for the sauce to begin taking on a glossier, caramelized hue. Then, remove the lid and transfer about half the sauce to a small dish.
Use a fork or small whisk to stir paleo flour into the liquid that was removed from the pot. Once the flour has mixed into the liquid, pour it all back into the pot. Keep the heat at a simmer, and let the sauce simmer openly for 3-4 minutes. Stir the sauce occasionally to check the thickness. When the sauce has reduced to a loose gravy texture, you can take it off the heat to cool before using.