This it the last time we are going to answer this question. The ingredients of heavy cream are … heavy cream. It is not a dish. There is no recipe for it. It is cream with 36 percent or more butterfat.
If you have access to fresh milk from the cow (i.e., not separated, not homogenized, not pasteurized), you can leave the milk out in a flat container and within about 24 hours, the cream will have risen to the top and you can scoop off your own homemade heavy cream.
Both the cream and milk left behind will have soured a bit, but the slightly soured flavor was a part of cream and butter until modern processing methods were developed. If you allow the cream to rise in a refrigerator, you can skip the souring process. If you have centrifuge and raw milk, you can make your own heavy cream in a matter of seconds and skip the entire waiting/souring process.