It's no ordinary chili pepper, lol. You will die if you eat a serrano chili pepper they're so hot! If you ever use them to make fresh salsa, you have to use plastic gloves because what makes your tongue burn when you eat spicy things... the same thing happens to your fingers, and you'll be up all night in searing pain!
Don't let that scare you though... in small, chopped up portions it really flavors up the beef, lol. Just cut the pepper in half lengthwise, and scrape out the seeds into the garbage (NOT UNDER RUNNING WATER IN THE SINK, the fumes will make you choke)