After I cooked a pork shoulder last week, I simmered the bone and trimmings with a lamb shank bone and some chicken wing tips for a day. I strained it and refrigerated it.
Today, I scraped the fat off the top of the broth and fried 2 carrots and an onion, diced, in it. I added the broth and simmered the carrots and onion for about 20 minutes.
Meanwhile, I chopped a couple cups of pork shoulder meat. I added it to the broth and simmered it for another 20 minutes. I tasted the broth and added salt, pepper, and some soy sauce.
I stirred some well-washed spinach in just until I wilted. Then I ate it with sour cream and onion cheese curds. (An odd impulse purchase today, but they did taste good in the soup.)