* Preheat oven to 400°F.
* In a small bowl, combine poultry seasoning, garlic powder, salt and pepper.
* Cut a pocket in each chicken; with chicken breast skinned side down, insert a sharp knife into the thinner end following through to the thicker end and create a lengthwise pocket being careful not to puncture sides of chicken breast.
* Insert one slice of Saint André® cheese into each pocket.
* Rub each chicken breast with ½ tsp. of spice mixture.
* Fold each parchment sheet in half, and cut a large heart shape using folded edge as the center.
* Unfold each paper heart and place 1 cup of mushrooms on one half, near the fold. Place chicken skinned side up with the opening to the pocket folded under. (This is to create a seal). Sprinkle chicken breast with 1 tsp. each, olive oil and lemon juice. Continue with remaining chicken and mushrooms.
* Fold over other half of heart to enclose the chicken and mushrooms. Starting at the top of each heart, make small overlapping folds to seal the edges together. At the bottom of the heart, twist the last folds a couple of times and tuck under to make a tight seal.
* Bake for 25-30 minutes. Transfer packets to dinner plates and let sit for 5 minutes. Carefully cut an "X" in the top of each parchment package to allow steam to escape.