On my first trip to Catalonia, I watched my extended family members make alioli daily. As a devout mayonnaiseaholic, I was nothing short of giddy to see the liberal use of my favorite condiment. The women in the family always made it, except for the ones who happened to be menstruating at the moment (a sure-fire way to keep it from properly emulsifying), and they always used an immersion blender (a little less traditional, maybe, but terribly effective when the kitchen was already overflowing with people and food).
We ate it with vegetables and meats cooked in all kinds of ways-- roasted, braised, grilled. We ate it with fried potatoes, sometimes dusted with pimentón, sometimes not. My favorite way, though, was with the crusts of the sweet baguette that made an appearance at every meal. That garlicky bite made me swoon every time. —vvvanessa
Place the egg yolk in a tall measuring cup or tumbler with the garlic and a splash of the olive oil. Using an immersion blender, begin to blend the ingredients for a few seconds, until they are mixed. Add in another splash of oil and mix again. Continue adding in oil a bit at a time until about half of it is incorporated. From there, you can pour in bigger splashes of oil so long as you are making sure it is completely emulsified before adding in the next splash. At this point, you'll need to move the blender in a slight up and down motion to be sure everything is being incorporated, but you also want to be careful not to overbeat the mixture.
Finally, add in the salt and lemon juice and blend just to combine.
Serve alongside your roasted vegetables, cured meats, sweet baguette, and, of course, your patatas bravas.