Use nutritional yeast.
One teaspoon for an entire bag of Daiya Cheese is all you need.
But… be judicious with the yeast, more is not necessarily better.
The nutritional yeast gives your vegan cheese that tang, like a good cheddar or swiss.
I list the product Daiya specifically because it’s only potential allergen is xantham gum, it’s texture and flavor are great already and it melts like a dream.
If you’ve never tried their cheeses, learn more about Daiya’s products at http://www.daiyafoods.com/