Start by cutting off the stem end. If you want to cut rings, simply make crosswise cuts the length of the pepper. Otherwise, cut the pepper in half lengthwise.
If you prefer a less spicy dish, use a spoon to scrape out the seeds and ribs. If you want an extra kick, leave them in.
Slice the jalapeño lengthwise into strips—thin strips if want minced peppers, or slightly thicker for diced. Line up the sliced strips on your cutting board, then use the paring knife to dice or mince the strips.
Notes
Remove your gloves carefully. Avoid touching your eyes or any other sensitive parts of your skin—sometimes you might not realize there’s oil on your hands, but you definitely will realize it if you touch your eyes.
If you need to cut a jalapeño and you don’t have gloves, some people say you can coat your hands in vegetable, canola, or olive oil to prevent getting pepper burns. Of course, if you use this method, be extra carefully when handling your knife!