While shishito peppers are typically mild, every now and then, you'll come across a fiery one. If you prefer spice, you may be tempted to remove the seeds before cooking. However, I recommend against this. The seeds are actually where the majority of the heat is concentrated, so removing them will result in a more bland flavor. If you want to reduce the spice level without sacrificing flavor, simply cut the peppers into smaller pieces so that there is less surface area for the heat to travel. Whatever you do, don't be afraid to experiment with these delicious peppers - they may just surprise you.