*I cut the chicken breast into large chunks - I don't want to put in an entire chicken breast without cutting it because I think it'll cook faster if it's in chunks, but you don't want the pieces too small because it makes the chicken harder to shred once everything's finished cooking. [br]**You can use store-bought pesto or homemade pesto. I used homemade pesto in this recipe (made with basil leaves, walnuts, cashews, almonds, lemon juice, and a little bit of olive oil), but you can absolutely use store-bought pesto.