In this Homemade Natural Immune Booster Recipe if you don't find Mint and Basil leaves , you can use the powder form as 1 Tsp. Mint Powder and 1/2 Tsp. Basil powder and you are good to go. You can also dry the remaining mint leaves and basil leaves under the sun for a day or in the oven for 30 seconds and roast them for a minute or two , make powder and store.