To a cocktail shaker add in your agave, jalapeño slices, and lime juice. (option to add ingredients like: chopped cucumbers, fresh strawberries, etc.)
Muddle until fully combined and mushed together, don’t be scared to put some elbow grease into this, you know what I mean?
Add in Cointreau and tequila, then add ice and shake.
Double strain into a glass with a fresh cube. Or, do a dirty dump: aka dumping your shaker tin right into the glass, shaken ice and all.
Garnish with a jalapeño slice and lime wheel.