I have chicken breasts stuffed with rice. How long should I bake them and at what temperature?
The time and temperature can vary widely based on a lot of different factors. What's important is the final temperature. Chicken breast is safe and largely considered palatable at 165F (74C). Use an instant read thermometer in the thickest part of the breast.
Just to give you an idea where to start, here are several recipes for Stuffed Chicken Breasts from Cooking Light.