Peel the potatoes and pumpkin, remove the seeds, cut them in cubes and boil them together until they're soft (it's better to overcook than undercook!).
Drain the potatoes and pumpkin, let them cool down until cold enough to handle. Next you want to mash the potatoes and pumpkin. I used a potato ricer for that. You should have about 1 1/2 cups of mashed potato and pumpkin together.
Add the salt and flour and knead it with your hands until a smooth dough forms. You can add more flour here if you feel like it needs more, otherwise I'd recommend breaking off a small part of the dough and make a test round.
Bring a large pot with water to a boil and add in the test-gnocchi. Let it cook for about 2-3 minutes. Once it swims on the surface, it's ready. Try it. If your test-gnocchi is too mushy and soft, add more flour to the dough and knead again until incorporated. If you're happy with the fluffiness and consistency, you can quarter your potato dough and roll it into a rope on a floured surface. Then cut them in individual pieces.
Transfer the gnocchi into the boiling water (work in batches) and let them cook until they swim on top. Use a skimming spoon to drain them, rinse them under cold water and set aside.
Heat olive oil in a large sauce pan, pan-fry the gnocchi until crispy. Add dried oregano, baby spinach (until wilted) and salt to taste. And enjoy!
Notes
Can you freeze gnocchi? Absolutely! After boiling them, drain them, rinse them under cold water, let them cool off, fill them into a ziplock bag or freezer-safe glass container and freeze for up to a couple of months. How to reheat frozen gnocchi? If you want to use your frozen gnocchi, boil them in a pot of water again until they float on top (make sure to try one gnocchi so that they are not frozen in the middle), then pan-fry or add the sauce. They are good as new!