Take chicken breasts out of the fridge and let them come to room temperature.
Preheat oven to 375F/190C and spray baking dish with non-stick spray. (I used a dish that was 8" x 11" but something close to that will work fine.)
Drain can and chop black olives, chop green olives, chop red onion, and chop capers.
Mix chopped black olives, green olives, red onion, and capers with Dijon mustard, garlic, lemon juice, and 2 T olive oil to make the topping.
Trim chicken as needed and season with Poultry Seasoning and a little salt and pepper.
Heat other 1 T olive oil in a large frying pan and brown the chicken about 5 minutes per side, or just until it's nicely browned. (It will not be fully cooked at this point.)
Cut chicken into 3 or 4 lengthwise strips (Make 4 strips for large chicken breasts or 3 for smaller ones. You want the strips to be about the same thickness.)
Arrange chicken strips in a baking dish. (I used a dish that was 8" x 11" but any size close to that will work.
Spoon the olive and caper sauce over the chicken, trying to get all the pieces of chicken covered with sauce.
Bake 20 - 25 minutes, or until the chicken is cooked through and the whole dish is bubbling hot.
I would use an Instant Read Meat Thermometer if you have one to check that chicken has reached a temperature of 165F/75C after 20 minutes, and cook it a few minutes longer if needed.
Serve hot, with the sauce and pan juices spooned over the chicken strips when you plate it.
