Trim and butterfly the chicken breasts. (Cut them in half from one side until you are approximately 1" from cutting through completely.)
Mix the spinach, cheeses, butter, chives, and garlic in a bowl.
Portion out and spread the mix on the inside of each butterflied chicken breast. Top the mix with portobello slices if desired. Fold and close the breasts over the mix.
Wrap each breast with 2 strips of bacon. Secure with soaked toothpicks as needed. Coat with Purely Seasoning Original to taste.
Place the breasts onto a parchment paper lined pan. Cook for 30-40 min at 375º F depending on breast size. Then turn it up to 400º F for 15 min or until you reach 165º F internal and the bacon starts to crisp up.
Remove the toothpicks, serve and enjoy!