The step that will take the most time is collecting the ingredients from the refrigerator and pantry!
(I used a bullet blender but you can use almost any blender.)
1 c olive oil (or any oil you prefer - I like the olive oil's flavor)
1 tsp lime juice (or lemon juice or vinegar - I like the lime flavor)
3/4 tsp salt
1/4 tsp dry mustard
1/2 tsp fresh tarragon (optional)
Using the bullet's flat blade, place the egg, 1/4 c olive oil, lime juice, salt and dry mustard in a tall bullet jar. Pulse for 10 seconds, three times. Add another 1/4 c. olive oil, pulse three times. Continue 1/4 c at a time until all oil has been incorporated. You will never buy store-bought mayonnaise after you've made your own. It takes almost no time, is delicious, you know exactly what's in it, and you know it's fresh and hasn't been sitting in a hot warehouse for a year.