Preheat the oven to 350oF and lightly oil or coat an 8x8 casserole dish with a non-stick spray. Place cashews, milk, lemon juice, garlic, salt, yellow mustard, and nutritonal yeast into the blender. Blend for 1-2 minutes until the contents are smooth. Pour into a medium bowl and place aside. Next, slice artichokes into small pieces OR you can chop them in a food processor. Add the chopped artichokes along with the spinach into the bowl with other ingredients and stir well. Finally, pour everything into the casserole dish and bake in the oven for 30-40 minutes