Preheat your oven to 350 degrees. Lightly grease a small casserole dish - I used a 2 quart dish. Place the chicken in a single layer in the dish.
In a small saucepan, melt the butter over medium heat. Add the onions & saute until soft and translucent. Add the garlic & saute just until fragrant. Remove from heat & add in the paprika. Pour the onion mixture over the chicken in the dish. Cover with foil & bake until the chicken is cooked through & no longer pink, about 45 minutes to an hour depending on the size of your thighs.
While the chicken is cooking, steam the broccoli until tender-crisp.
In a small bowl, mix together the sour cream, mayo & Parmesan cheese. Set aside until the chicken is done cooking (I put mine back in the fridge because I'm weird about mayo sitting out for more than like two minutes).
Once the chicken is cooked through, remove the dish from the oven & turn the broiler on on your oven. Arrange the broccoli and the peach halves around the chicken thighs. Dollop the sour cream sauce on top of the chicken, broccoli & peaches.
Return to the oven & broil until just brown.