Heat the olive oil in a medium pan over medium-high heat. Add the onion and the cabbage with a good pinch of salt and cook, stirring occasionally, in order to cook down the cabbage. Avoid stirring constantly to and allow the cabbage to brown. If needed, add a splash of water and put the lid back on the pot and allow to cook on medium-low heat for a few minutes to allow the cabbage to wilt. It is important that the cabbage gets browned and wilted to add depth of flavor to the stew!
Add the chopped carrots and allow to cook for a few more minutes then add about 3 cups of broth and bring to a boil while you cut your potatoes.
Add the potatoes, white beans (or white beans and chickpeas), Thyme, crushed red pepper, vinegar, and tomato paste. Mix all together. Add more broth, 1 cup at a time, until broth until it is just at the top of the mixture so that it stays a thicker consistency.
Taste the broth to make sure that it tastes balanced. If needed, add more salt and pepper. As the stew cooks it will also slightly change in flavor.
Bring to a boil, reduce to a simmer, cover, and allow to cook for about 10 minutes until the carrots are almost completely soft and the potatoes are fork tender. If you would like a thicker consistency to the stew, remove 1 cup of the stew and blend in a blender or with an immersion blender and then add it back to the pot. This gives the broth a nice thick consistency.
Once the stew is almost finished cooking, add the spinach or kale and cook for a few more minutes until wilted.
Enjoy! This stew stays good in the fridge for 4 days and freezes well for longer storage.