From the Peafowl Stickies:
https://www.backyardchickens.com/t/388465/peafowl-101-basic-care-genetics-and-answers
Housing:
Adults can either be kept in pens (usually for breeding or if you really dont want to find out if your pea will stay or leave if you let it free range) or be allowed to free range. Whether or not they free range, they should have access to an indoor area where heat can be provided (especially in winter). They can have free access to ground by now. Chicken wire and wooden enclosures seems fairly typical for them. Enclosures should not be smaller than 10x20x6ft high, and it should definitely have a top. Roosts/perches should be provided and it is best for these to have flat surfaces. In the winter, a round roost will leave their toes exposed overnight and can lead to frostbite. If you are allowing a male to free range, it is a good idea to keep a female penned to increase the chance that he will return.
Food:
Adult birds can be fed gamebird maintenance crumbles/pellets. You can feed them normal chicken food but it will not have sufficient protein. We made up for this in the past by feeding them kitten hard food as a supplement/treat. If they are penned without access to dirt or pebbles, they may need supplemental grit.
Treats for adult birds can be: hardboiled eggs, melons (watermelon, cantaloupe, etc), squashes, tomatoes, greens (spinach, lettuce, etc), beans, crickets, wet cat food, pasta, rice, raspberries, strawberries, blueberries (etc), peas (har har, feeding peas to peas), cucumbers, bread (may want to moisten), peanuts, raisins, cooked meats (never raw or partially raw), grapes, corn well, you get the picture.
There is additional information about peafowl housing and roost requirements here:
https://www.backyardchickens.com/t/394024/peafowl-102-advanced-housing-and-accessories#post_4768364