Crack an egg into your immersion blender cup or tall mason jar. 

Next, pour oil and the strained lemon juice into the cup or jar. 

Crush garlic clove into the mixture. 

Using an immersion blender, hold the blades to the bottom of the oil and blend, gently moving the stick up and down in your container. 

Once the liquids start to emulsify, slightly tip the blender stick to let the oil gently move from the top to bottom under the blades to incorporate all liquid. 

After about 30 seconds, the mayonnaise should be ready and thick. Turn off the blender stick and gently remove it.