In a dutch oven or thick bottomed pot, heat the olive oil over medium heat. When almost smoking, add pancetta, onion, garlic, rosemary and sage. If you don't have fresh sage use a teaspoon of dried. After about a minute, add fresh red pepper (but only if you want the soup spicy, just skip this step if you don't). Cook for about 5 minutes. Stir frequently. Add the tomato paste and continue to cook for about 3 more minutes. If you don't have tomato paste, a small amount of jarred pasta sauce will work too. Add the beans to the pot, and stir in for about 2 minutes. Then add chicken stock and half cube of tomato chicken bouillion (another optional step). When the soup boils, reduce heat and add spinach or arugula. The soup is ready to serve two minutes later.