Measure the ingredients into a blender and blend until very smooth. A hand blender will also do the job.
If you like, you can thin the Hoisin Sauce with a couple of tablespoons of boiled water. Boiled water is cleaner than tap water. It could extend the shelf life of the sauce if you don't use it all at once. Keep it in fridge.
Notes
For a quick Hoisin Pork: Fry strips of pork tenderloin in a wok. Simmer for a few minutes in Hoisin Sauce. Stir in the veggies, fry for a minute and serve with the cooked noodles.