Melt the butter in a pot. Add the pork and cook until nicely browned. Trust me, the browning process will add so much flavor and texture to the cooked dish so don’t skip this step.
When the meat is nicely browned, add the chopped onion and continue cooking, with occasional stirring, until the onion bits start to soften.
Pour in five cups of broth. Stir and remember to scrape whatever bits may be stuck in the bottom of the pot. Taste. Add salt and pepper, as needed. Bring to the boil.
Add the chayote. Bring to the boil once more then lower the heat, cover and simmer for about 10 minutes.
Dissolve the soup mix in the remaining broth. Pour into the pot. Taste. Add more salt and pepper, if needed.
Add the squash. Bring to the boil, lower the heat and simmer for another 10 minutes or until the squash is done and the soup leaves no flour-y sensation in the mouth.
Stir in the spinach leaves. Cook for another minute.
Serve the mushroom soup with pork and vegetables hot with buttered bread.