In a small bowl, mix together salt, pepper and Italian seasoning.
Cut a lengthwise slit into each chicken breast to create a pocket, being careful not to cut all the way through.
Sprinkle the seasoning mix on both the inside and outside of the chicken breasts.
Gently open the pocket of each chicken breast and place 2 slices of cheese and 3-5 spears of asparagus in the center. Then add a squeeze of lemon juice, a splash of balsamic vinegar, and another slice of cheese on top.
Seal the pocket of each chicken breast using several toothpicks.
Pour 1 cup of water into the bottom of the Instant Pot insert, add in the trivet, and then place the prepared chicken breasts on top of the trivet.
Close the lid, turn the valve to sealing position, and set to high pressure / manual pressure for 7 minutes.
Once done, allow for an 8-minute natural pressure release, then manually release the remaining pressure.
Optional: To brown the stuffed chicken breast before serving, remove the chicken and the trivet, set the Instant Pot to sauté mode, add some olive oil and then return the chicken to the bottom of the Instant Pot insert. You can also brown the chicken in a skillet on the stovetop if you prefer.