Heat the Instant Pot using the Sauté function and add the butter.
1 tablespoon butter
Once the butter has melted, add the carrots, celery, onion, and mushrooms to the pot and stir to coat all of the vegetables with butter.
2 large carrots, 2 large stalks of celery, 1 medium onion, 1 cup sliced button mushrooms
Cook for 5 minutes, or until the vegetables are tender and starting to brown.
Next, add the garlic and sage and cook for an additional minute.
2 cloves garlic, 1 teaspoon fresh sage
Add the chicken stock, turkey, noodles, salt, pepper, and bay leaf and stir to combine.
4 cups chicken stock, 2 cups shredded cooked turkey, 2 cups uncooked egg noodles, 1 teaspoon kosher salt, ¼ teaspoon black pepper, 1 dried bay leaf
Attach the lid and ensure the valve is in the sealing position. Set the Instant Pot to Pressure Cook - Manual for 3 minutes (see notes).
Once the Instant Pot has finished cooking, release the pressure manually by switching the valve to the venting position. Be careful, it may spit and steam when the valve is opened!
Remove the bay leaf and adjust the salt and pepper as needed. Serve warm.
Store any leftover soup in an airtight container in the fridge for up to three days.