With a total of 5 minutes and some patience, you have this jalapeno tequila.
First, wash and slice your jalapenos. Keep the seeds in! Also, don't worry about thinly slicing, you can make thicker slices.
Next, place your jalapenos in your air-tight container. Pour in your 750 mL of tequila. Close the container and place your tequila in the fridge for 1 - 2 days.
Taste test your tequila after a day to see the spice level. If you want a bit more bite, let it sit and infuse for a bit longer.
After you let your tequila sit, remove the jalapenos. Keep your tequila in the fridge and use it to make all your favorite spicy cocktails.