Put aluminum foil on a cookie sheet.
Put all of the chicken breasts on the sheet. (Tip: If the breasts are super thick, cut them in half to make them thinner. They will cook faster and be more tender.)
Season chicken breasts however you would like - salt and pepper, barbecue sauce, fajita seasoning, etc. You can even cook different seasoned ones all at once.
Cook in oven. I find that about 20 minutes at 375 usually works, but keep an eye on them, and check to make sure they are done - not pink in the middle. (Tip from Zane's mom: The safe internal temperature for chicken in 165 degrees. You can buy an instant-read thermometer to check.)
Eat one of the breasts for your meal and save the rest to eat later.