Candy, I assume you know how to make mayo, but I'll give the complete instructions for the people who have never tried it.
I start out like any other mayo, with an egg, 1/2 tsp salt, 1/2 tsp dry mustard in the blender. Blend, add 2 tbsp lime juice, wipe down the sides, blend again. Pour in some oil (preferably EVOO for this recipe) in a very, very fine trickle (that part is extremely important) until the blades are nicely covered. Then throw in your avocado, cut into chunks, (peeled, of course, duh) and at least one good-sized clove of garlic. A little hot sauce or cayenne can be added too, for those who like to spice things up. And cumin, if you want to give it a bit of a Mexican vibe. Blend thoroughly. You'll probably have to stop the blender pretty often to push things down toward the blades. Then continue slowly adding oil until it reaches the consistency you prefer: nice and thick for spreading or dipping, runnier for salad dressings. In the latter case, you might want to add some vinegar or extra lime/lemon juice too. I can't specify the exact amount, because avocados come in so many sizes. I had a huge one this time, so I didn't need a lot of extra oil. A useful trick I have found for adding oil gradually is to NOT fill the measuring cup. It is much easier to get a thread-thin stream out of a half-full cup, no matter what the size.
I was not fully awake when I made this and used the light olive oil, and it really wasn't as good. The avocado smooths out the taste of the extra-virgin olive oil, which tends to be overpowering in a straight mayo, but goes together really well with garlic and avocado. Anyway, so far so good. No sign of browning even after a couple of days.
***
Sometimes my body tricks me. Most of the time, I can really tell when I'm at or near a new low. Today I felt fat when I woke up, but the scale did not agree. I barely edged past the previous low, but there it was: 145 even.
Hey, I'll take even a couple of ounces. Especially because yesterday I made "primal" pancakes (not entirely, because there is some tapioca flour in there to give them a smoother texture) and then ate a double helping... *sigh* So it was my only meal of the day, which was no hardship. I am absolutely astonished at how easy it is to go for hours without eating and not feel any negative effects. Mind you, I did have a bit of chocolate later in the day and it actually filled me up. 
I'll have to be good for the rest of today, in anticipation of the restaurant outing. And all the opportunities for over-eating that the coming weekend holds. I think I am perfecting the art of moderate feasting...
5'2", 55 years, Primal since April. Pre-Primal weight loss, from 216.6 to 157.8
Primal low: 140.2 (Dec. 3) Goal weight: 135?
Main Primal goal: beating back my CFS enough to function more normally and start writing again
More and more, our life has been governed by specialists, who know too little of what lies outside their province to be able to know enough about what takes place within it.
- Lewis Mumford