Add 1.5 oz tequila, 2 oz watermelon juice, 0.75 oz lemon juice, and 0.75 oz mint simple syrup** in a shaker. Dry shake for 10-15 seconds, pour into a secondary container. Work through 4 batches shaking the ingredients until all are incorporated then set aside in the secondary container. In a non-reactive container, add the cold milk. Slowly pour in the full cocktail batch into the milk. Stir. Let set for a few hours in the fridge to let the milk do its thing (a.k.a. curdle) do not stir. When the whey has formed into a skin in the container and settled to the bottom, it’s time to strain. You can leave it for up to 24 hours. Line a strainer with cheese cloth. Slowly pour the mixture through the cheese cloth (Can take hours). Allow the ingredients to collect in a container. After all of the batch has been poured through, pour the now collected liquid through a coffee filter untill clear. May take several passes. Once clear, you have a milk punch that can last several months in the fridge.
**Mint Syrup (1:1): Heat equal parts of water and sugar in a saucepan. Stir frequently until sugar is dissolved. Turn heat off and add 3-5 sprigs of fresh mint to the hot syrup after spanking the mint. Stir on occasion and let it steep for 10-15 minutes. When the pan is cool enough to touch move it to the fridge and let it finish infusing for 12-24 hours. Remove the mint and strain the syrup. Label, date, and store in an airtight container in the fridge for up to 1 month.