Use non-stick spray or a crockpot cooking liner to cover the inside of your crockpot.
Heat Avocado or Olive Oil in a large saute pan over high heat and add beef strips. Depending on the size of your pan you may need to work in batches. Season the beef strips with salt and pepper and quickly brown, about a minute on each side. Add to crock pot.
Saute onions and garlic over medium-high heat until lightly browned and tender 2-3 minutes. Add to crock pot.
Add sliced mushrooms to the crock pot and gently stir all ingredients to combine.
Add 1 cup beef broth, Worcestershire, Soy (Tamari) and Dijon. Cover and cook on High for 3 hours or low for 6 hours.
When cooking is complete, set the crock pot to Warm. Stir the cornstarch (gluten-free Cassava) together with the reserved ½ cup of beef broth to create a slurry. You may need to add a little more cornstarch or flour to get a thicker consistency.
Gradually stir the slurry into the crock pot and cook on High for 20 minutes. Stir often.
Once the slurry has thickened the sauce, reduce the heat again to Warm and slowly stir in the Coconut Milk. Stir continuously to prevent curdling.
Ladle Beef Stroganoff over bowls of noodles, zoodles or rice and top with fresh parsley for serving.