In a wide-mouthed jar blend the egg, egg yolk, 1 t-spoon of lemon juice, garlic, and salt on medium speed for about 1 minute to aerate the egg and bit and combine everything. Now, with the blender still running, slowly stream the basily oil (plunging the immersion blender up and down a bit). Start by doing it drop by drop, slowly increasing it up to a thin, steady, slo-mo stream. Once it’s smooth, thick, and perfectly emulsified check it for seasoning and add more salt or lemon juice as needed.