Turn on the Instant pot and select the Sauté button.
Add 1 ½ cups of low-sodium chicken stock. Stir in French onion soup mix (stir properly so that there are no lumps), mix, and add garlic.
Add chicken breasts to the stock. Next, evenly top with diced mushrooms and place the block of cream cheese in the middle, do not stir as it will melt while cooking.
CANCEL the SAUTE button. Select the PRESSURE COOK button on HIGH PRESSURE for 15 minutes. (Make sure the valve is in the SEALING position).
Once the pressure-cooking cycle is over. Allow pressure to release naturally for 5 minutes then quick release pressure by manually moving the valve from SEALING to VENTING position.
Select the CANCEL button and take the lid off carefully.
Remove the chicken pieces, shred them and set aside.
Select SAUTE button, whisk the soup with the help of a spatula, and let the soup simmer for 2-3 minutes.
Return the shredded chicken back to the soup, along with finely diced spring onions, and stir through.
Select the CANCEL button.