Peel and cut the mango into chunks, then puree it. You want it to be relatively smooth. I find it best to add a few tablespoons of simple syrup when pureeing it to help facilitate that. NOTE: Now, mangos are pricey (even when they are in season) so if you want to use just one, you can. Or even use frozen mango chunks for this. You just need to let them thaw out completely. If you use frozen mango chunks, you will need about 2 cups of frozen mango.
Add the serrano chile, sliced, to a cocktail mixer. Add the 1/4 cup of tequila and depending how spicy you want it, you can muddle the chili in the tequila or just let it infuse. If you are overly sensitive to heat, use just a quarter of the serrano the first time you make this recipe. This baby has some kick! If you like a lot of heat (like me), use the whole damn thing. Yum!
Once the mango is fully pureed, pour it into a measuring cup that holds at least 4 cups. If you used fresh mangos, you should have about 1 1/2 cups of puree.
Straining out the serranos, add the 1/4 cup of tequila. You can also adjust the heat here. Add in just half of the tequila and give it a taste. Keep in mind, it will be less spicy once frozen.
Juice the lime and add it to the mixture.
Now add the simple syrup. This recipe is designed around the popsicle mold I have which holds 3 cups total across 10 popsicles. So for this mold, add the simple syrup so that you have 3 cups total between the mango puree, tequila, lime juice, and the simple syrup.
Whisk the mixture well and then divide it amongst the popsicle mold. If you want, you can do what I did and add in thinly sliced serrano chilies for texture.
Add the popsicle sticks and freeze them for at least 7 to 10 hours, until they are rock hard.