Put the pith and seeds from at least 2 of the peppers in the tequila and allow to sit for an hour or so, then remove. Depending on how spicy you want it you can add more pith and seeds and / or let sit for longer
rough chop the jalapeno rinds and combine in a blender with the remaining mix ingredients. Blend on high for at least 30 seconds. You want the rinds to be as pureed as possible
Pour the mix through a strainer into a container. Use a silicone spatula to press all the liquid through the strainer, leaving the jalapeno mulch (discard)
When it's time to serve combine mix and tequila. Depending how fast you expect this to go, either combine with ice in the jug or serve over ice as needed. If the ice is in the jug it will melt and dilute the mix.
If garnishing with jalapeno slices, remove seeds, but keep pith where possible.