Legally, can I sell cooked food from my house?

You cannot sell prepared foods from your home without having the appropriate permits. In fact, some states prohibit the sale of home canned foods altogether. There are a host of health and safety issues (like, how clean IS your kitchen?) that are involved in starting a food-based business.

Speak to an attorney who specializes in food businesses in your state to get a list of the legal requirements. Your state and local food/agriculture departments will have information for you, too. You'll have to pass health inspections, meet possible zoning restrictions, and will have FDA regulations involved.

Don't forget the need to incorporate, obtain a sales tax license and obtain insurance. In short, don't move forward on this idea without the benefit of professional advice from people who actually speak to you about your particular situation.