(1) Remove the ribs and seeds from all four jalapeños, and roughly chop the flesh of one jalapeño.
(2) Add the ribs, seeds, and chopped flesh to the tequila in a large container and let sit at room temperature for 20 minutes. Taste. If you like the spice level, strain through a fine mesh sieve and store in the fridge. If you want more spice, let sit for another five minutes and taste again. Continue until you reach your desired heat level.
(3) Pour into pre-chilled salt glasses and serve immediately with a slice of lime.