Pour the egg whites in a bowl, together with the mashed garlic clove, lemon juice and salt. Use 0.5 clove for a light garlic touch, and use the full clove if you want a more distinct garlic flavor. I use a so called micro planar to shred the garlic clove. Start whisking until the egg white mix turns white and fluffy. I use a hand whisk for this.
It usually takes 1-2 minutes. A word must be said about the oil: use a neutral oil. Canola oil works, but adds a slightly metallic flavor, and olive oil is even worse, taste wise. That is why I recommend peanut oil. Now start adding the oil very slowly, whisking steadily all the time. The trick is to get the egg whites to bind the oil, or hold it in suspension. Keep pouring the oil very slowly, and keep whisking until all of it is mixed. It usually takes a few minutes, but that’s better than when the sauce splits. The more oil, the thicker the cream. So if you feel like a thicker sauce, add more oil.