You can adjust the proportions to fit your taste. As written, the recipe makes about enough to fill a 2.3-ounce jar. You can change the unit of measure to teaspoons instead of tablespoons to make less or to cups to make more (that would be a HUGE amount!)
Mix all ingredients together and store in an air-tight container. Note: if you use onion flakes that are larger than the other ingredients, you may crush them lightly in a mortar and pestle before mixing them in.
Somehow my version came out lighter than Trader Joe's original, which lists 5 calories per 1/4 teaspoon. I deliberately used less salt, so mine contains less sodium than the 80mg in the original.