Press, "Sauté," on your Instant Pot.
Add 2 t. oil and then also spray a non-stick skillet with a bit of oil from your Misto sprayer.
Add onions and garlic and cook for about 2 minutes, stirring occasionally and spraying a bit more oil if needed.
Add chicken and cook for about 1 minute. Turn off Instant Pot.
Add ham, broccoli, rosemary, sherry, Worcestershire sauce, salt, pepper, chicken broth, and cream cheese on top. Do not stir in cream cheese, just set it on the top.
Cover Instant Pot with lid, set to seal, push, "Manual," or on some models, "Pressure Cook," and set for 3 minutes. Yes, really 3 minutes! It takes a while for the Instant Pot to heat up so by the time the 3 minutes is up, the chicken is cooked perfectly.
When time is up, do the "quick" release and open pot.
Stir in Swiss cheese and Parmesan. If it doesn't melt all the way, push the, "Sauté," button and stir until mostly melted. If you want it a bit thicker, place about 1/4 c. sauce mixture in a cup, add 1 T. cornstarch, stir well and put back into Instant pot. Cook until thicker. (Note: This sauce does thicken up after cooling.)
Serve immediately over butternut squash noodles, zucchini noodles or pasta (add more points for pasta). (See note at bottom for noodle directions.)