I currently work in home office but in the late afternoon I pick up my kids from school, we spend some time on the playground and usually only come home half an hour before dinner time. For soups I used the strategy to set them up during my lunch break and then let them cook for half an hour. Then turn the stove off and put it back on when we come home. The soup is ready just at dinner time. I was wondering whether I can do the same with a roast chicken in the oven. That is I put in the oven around noon, roast for half an hour and then turn the oven off, leaving the chicken in. Turn the oven back on when we get home. Have ready roast chicken at dinner time. I was mostly wondering whether there is something that could go wrong here? Will this turn out any different from just roasting a chicken for 1 hour without breaks in between? 
Can it be done?  yes. Is there a higher risk of food poisoning?  yes. The way to get around that is almost more of a pain -- you cook it in a low oven until it's just barely cooked through (which is a different temperature for the legs vs. the breast meat), then chill it, and then return it to a hot oven to warm it and crisp the skin up. You're often better off fully cooking it, chilling it, and then warming it back up, and serving with a hot gravy that you can pour over it. Another alternative would be spatchcocking the chicken (cutting the backbone out and flattening it, so it cooks quicker; see https://www.seriouseats.com/butterflied-roasted-chicken-with-quick-jus-recipe ).  You could prep it in advance, so you just had to throw it in the oven when you got home ... but you have to cook it under the broiler for a chance at the 30 minute window: https://www.foodnetwork.com/recipes/alton-brown/broiled-butterflied-chicken-recipe-1951266 ) There's also a technique where you quarter the chicken, start it on the stovetop (starting the leg quarters first), then move it to the oven that's been pre-heating ... and if you had the chicken prepped might take 30 minutes ... but I'm having difficulty finding the recipe.  (I thought it had been on Good Eats, but I'm not having luck searching the Food Network website). 