a widemouth jar of one half to one pint capacity
a cup of oil- any oil. I almost always use extra virgin olive oil, but canola is a good, healthy choice. Some people like half olive oil and half canola. Light olive oil is a good choice if you want a lighter flavor.
a half a large lemon, squeezed through a strainer (or 2 tablepoons prepared lemon juice)
a quarter teaspoon of salt
a half teaspoon (or more) of crushed garlic
a teaspoon of powdered mustard, or a tablespoon of prepared mustard, or a teaspoon or more of your favorite hot sauce. (Or, for those who like- yuck!- Miracle Whip, two teaspoons of sugar)