Here is a great recipe for vegan mayonnaise. I used to buy Nayonnaise at Whole Foods but at over $4 a bottle, it got to be very expensive. This one tastes great and lasts a few weeks.
4 ounces of silken tofu
1 tablespoon of canola, sunflower, or olive oil
1 tablespoon of apple cider vinegar
1/4 teaspoon of ground mustard seed (use 1/2 of grinding whole seeds as I do)
1/2 teaspoon of sea salt
Optional - turmeric, paprika, and/or garlic powder to taste
Blend all in a blender. A hand blender works fine.
Note: When I can't find 4 ounces of silken tofu, I buy 8 ounces. You can either double the recipe or use the extra silken tofu for a smoothie. I add frozen strawberries, banana, maple syrup, and juice (save the juice from canned or frozen fruit). My daughter usually has it with breakfast.