Spinach Avocado Stuffed Mushrooms! 1. Bake 8-10 baby portobello mushrooms (lightly drizzled with olive oil), cap up without stems in a preheated 450 degree oven for 7 minutes. 2. Blend the filling: 1 1/2 c spinach, 1 garlic clove, 1 medium avocado, 1/4 c walnuts, 1 tbsp each of nutritional yeast and lemon juice. Add salt for taste 3. Spoon into mushrooms and serve or stick it into the oven again at 450 degrees for 3-5 minutes 4. Add salt and almond garnishes for taste!