Rinse mussels under cold water. If your mussels have “beards,” pull them backward to remove. Discard all broken, cracked, or opened mussels.
Remove the lid from your Instant Pot. Press the “saute” button on the “normal” setting and wait until the screen says “hot.”
Add butter. When the butter is melted, add chopped onion and saute for 1.5-2 minutes or until translucent. Add garlic and chili flakes and continue to cook for one more minute.
Pour in ¼ cup of wine, give a stir, and saute for 1 minute to evaporate. Squeeze half of a lemon in, add chicken broth, and stir again.
Add mussels to the instant pot and mix to coat with sauce. Put the lid on and place the valve to “seal.”
Press “cancel” on your instant pot and then hit “manual” and adjust the time to 3 minutes.
When the time is up, release the valve. Be careful as the steam is hot!
Take the lid off and remove mussels from the instant pot. Pour with the desired amount of sauce, sprinkle with finely chopped parsley or mint if you want and serve with some lemon wedges. Enjoy!