Set your oven to 375 degrees Fahrenheit. Take the raw mushrooms, over the sink with a fork, carefully remove the stem and any excess on your mushroom wash, and set them on a paper towel to dry. After they are clean and dry, place your mushrooms open face up on a baking sheet covered in aluminium foil and lightly sprayed with pam. Bake for 3 to 5 minutes to soften a bit, then set aside.
In the meantime, saute your onion in a pan sprayed with pam over medium-high heat. When your onion is soft, add in your ground turkey with salt, pepper, and paprika and cook until golden brown.
Add your artichoke, spinach, cream cheese, nutritional yeast, cooked turkey and onion, and heavy seasonings in a microwavable mixing bowl. Microwave for 1 minute to soften the cream cheese, then stir until all ingredients are mixed well.
Take a spoon, and pack your mushrooms tightly with the mixture. Place your filled mushroom caps back in the oven for 5 to 10 minutes. You will know they are done when the tops are starting to turn a golden colour, but they have been in too long if your mushrooms are beginning to produce liquid (if this does happen, drain excess liquid). Serve hot or refrigerate for an hour and serve cold!