1. Preheat oven to 380F (~190C). Place pepper halves in a baking dish (cut side up), lightly season with salt, drizzle with avocado oil and bake in the preheated oven for 15 minutes.
2. Heat a large skillet over medium-high heat, add ground beef (no need to use oil) and break it up with a spatula. Move to one side of the skillet. Add chopped onion to the other side and cook until soft, for about 5-7 minutes.
3. Add chopped mushrooms, minced garlic and stir. Cook for 5 minutes.
4. Add tomato paste, water, chili powder, cumin, Italian seasoning. Season with salt and pepper. Stir and cook for another couple of minutes.
5. Remove peppers from the oven (there will be some liquid in the bottom of the peppers, no need to remove it), distribute the meat filling evenly among the pepper halves. Return to the oven and bake for 10 minutes.
6. Make the sauce. Add all the sauce ingredients to a blender jar, blend with an immersion blender until smooth.
7. Drizzle stuffed peppers with the creamy cashew sauce and serve.