In a medium bowl, whisk together the flour, baking powder, and 1 teaspoon salt.
Make a well in the center of the dry mixture and pour in the 1/2 cup milk and 2 tablespoons olive oil.
Mix together with a fork until combined. Set aside.
Set your instant pot to saute and wait for it to get hot.
Pour in the remaining 4 tablespoons olive oil.
Add in the chicken thighs, celery, carrots, onion, and baby bella mushrooms.
Cover with a regular pot lid and let cook, stirring occasionally, for about 5 minutes. The carrots should be soft.
Stir in the minced garlic and cook an additional 30 seconds
Turn off your pressure cooker.
Remove the lid and pour in the chicken broth, cream of mushroom soup, 1 cup milk, red pepper flakes, black pepper, and salt. Mix together.
Rip the dumpling dough into 1 inch pieces and toss on top of the soup mixture.
Close your regular pressure cooker lid on top of your instant pot and set to sealing.
Turn on your instant pot. Set to high pressure for 15 minutes.
Natural Pressure Release and serve immediately.