Chop onion and cook slowly with a bit of water in a frying pan until the onion is clear. The goal is to let the onion get sweet but not to brown it. If it gets slightly tan colored, no problem. If it gets dark brown and black crispy bits you've gone too far. It'll still be edible, just not the same.

Add all ingredients into a blender. Blend on low until it comes together, then put the spurs to it (higher speed) for about 30 seconds. That'll make sure it is fully blended.

Store in the refrigerator