Preheat oven to 425.
Add cashews, milk, lemon juice, garlic, salt, dry mustard, and pepper in a blender. Blend until smooth.
Add artichokes and spinach and pulse until chunky. (I don't really like describing food as "chunky", but you know what I mean. Keep some texture.)
Transfer to an oven-proof baking dish, and bake for 17-20 minutes. Remove, let cool for about 4-5 minutes, and serve.
If needed, sprinkle some vegan parmesan on top (we know this is processed, that's why we said IF NEEDED) and pop back in the oven for a minute or two.