Get 2 baking dishes and pour in some olive oil to coat. Arrange the pieces of chicken, the potatoes, onions, garlic cloves, and peppers on them. (If you want to use 3 dishes and have got the room, do; the less packed everything is, the crispier the potatoes will be.) Then drizzle some more oil over, making sure everything's glossy and well slicked (but not dripping), sprinkle with the salt, and bake for about 45 minutes.
When done (and test all the component parts), strew over the parsley and - I always do this - serve straight from the baking dishes.