Option 1: You can slowly, and steadily, add oil with one hand while using the immersion blender with the other hand, blending the steady stream of oil, eggs and spices together before it starts to thicken. This can be difficult to do alone, but not impossible. The mayo should start to thicken at about the halfway point - prime tasting time! Taste a bit of your mayo and then read the notes below if something seems off. If all is well, begin alternating adding oil and mixing until the mayo is almost at the top of the jar. You don't need to use the immersion motor every time you mix - manual mixing is a good idea towards the end to avoid breaking the mayonaise. The fuller is gets, the messier the job gets (and the easier it is to 'break' the mayo - see notes) so don't worry about filling the jar completely. I usually stop about an inch below the lip.
Option 2: Add a fair amount of oil (maybe ¼ cup) and emulsify on a low setting starting from the surface of the mixture and then gently blending the mixture by slowly pushing down and pulling up the other side to mix the oil with the egg/spice/vinegar combination. Once fully mixed, add more oil and emulsify again. The mayo should start to thicken at about the halfway point - prime tasting time! Taste a bit of your mayo and then read the notes below if something seems off. If all is well, repeat these steps until the mayo is thick and almost to the top of the jar. You don't need to use the immersion motor every time you mix - manual mixing is a good idea towards the end to avoid breaking the mayonnaise. The fuller it gets, the messier the job gets (and the easier it is to 'break' the mayo - see notes) so don't worry about filling the jar completely. I usually stop about an inch below the lip.
Option 3: Your third option is the more primitive, time-consuming option. The previous two options use more of the immersion blender motor, as this option uses a manual mixing method in addition to the motor. Add oil (about ¼ cup) and motor mix into your egg/spices/vinegar blend. Add another ¼ cup oil and motor mix again. After the first two mixes, at a little less than ¼ cup of oil and mix manually (don't use the motor). This is a great method when just starting out because it gives you an idea of the thickening process, when it happens and how the oil affects the process. Mix as much manually with this method, occasionally using the motor when it seems the manual mix isn't incoorporating the oil enough. The mayo should start to nicely thicken at about the halfway point - prime tasting time! Taste a bit of your mayo and then read the notes below if something seems off. If all is well, repeat these steps until the mayo is thick and almost to the top of the jar. The fuller it gets, the messier the job gets (and the easier it is to 'break' the mayo - see notes) so don't worry about filling the jar completely. I usually stop about an inch below the lip.
Once you have a lovely tasting mayo, slowly remove your immersion blender and use your spatula to get the excess mayo off the blender and into the jar (waste not!)
Enjoy immediately or place in the fridge to cool and enjoy later.