Drain the can of artichokes and set aside. Line a medium pot with a thin layer of water and turn the heat up to high. Add spinach, cover and cook until spinach is dark green, about 5 minutes. Turn off heat, drain and then transfer spinach, garlic, artichokes and non-dairy milk to food processor or blender. Process until smooth and creamy. Return mixture to pot and whisk in nutritional yeast and flour. Turn heat to medium and cook until thoroughly warm. Add salt and pepper to taste and serve.