One Pot Garlic Butter Chicken Thighs and Mushrooms

butter (divided)

salt (very small amount - but if using low sodium stock or unsalted butter, ok to use a little more salt)

chicken thighs (bones removed (skinless or with skin OK))

garlic (sliced in half or finely diced (I like big chunks of garlic but realize most don't))

cremini mushrooms (stems removed and wiped clean)

chicken stock

to 1 tsp red pepper flakes (depending on your desired spicy level)

diced cilantro (optional)

lemon juice

parmesan cheese