There’s more than one way to get the seeds out of a pepper, but some are more efficient than others.
Seeding sweet bell peppers
My favorite method for trimming bell peppers hardly disturbs the seed core at all, which means I don’t have many errant seeds to chase off the cutting board.
Begin by cutting off the bottom off the pepper and then stand it upright on the cut surface.
Now imagine the sides of the pepper are a box surrounding the seed core and cut off the four sides of the box, leaving the seed core and stem in one easily discardable piece. Trim the pithy white ribs from the sides and base, if necessary, and then slice or dice as needed.
Seeding hot chiles
Remove the seeds and ribs of a hot pepper with a spoon (or a paring knife).
When I’m working with hot chiles, my main concern is keeping the juices off my hands. Even after washing your hands, the hot stuff (called capsaicin) can linger on your skin and come back to haunt you later if you rub your eyes. The best way to prevent this is to wear a disposable rubber glove on the hand that holds the chile.
Cut the chile in half lengthwise and then, depending on how delicate the chile is, use a small spoon or a paring knife to scrape or trim away the seeds and ribs. Use your gloved hand or the knife to scrape the trimmings into the trash and wash the cutting board well to avoid transferring capsaicin to other foods.