Preheat your oven to 375 degrees F.
Lightly oil a rimmed baking sheet with 1 to 1.5 Tbsp of olive oil.
Place your chicken breasts on the baking sheet, flipping once to coat in oil. Generously season with Italian seasoning, plus salt and pepper.
Place in the oven and roast, flipping once, for 20-25 minutes.
While the chicken is roasting, prepare your vegetables. Dice two shallots and two ribs of celery in to bite sized pieces. Set Aside.
Once your chicken is done, allow a bit of cooling time - 10-15 minutes.
When the chicken has cooled, chop in to bite sized pieces. Add the chicken to a large bowl with shallots and celery. Stir to combine.
Add mayonnaise, salt, pepper, garlic powder and onion powder. Stir well to incorporate. Taste for seasonings and add additional salt and pepper as needed.
Serve your chicken salad on a buttery croissant, a bed of fresh garden lettuce or Italian bread for a simple, delicious and wholesome lunch. Enjoy!
