Heat oil in a skillet over medium high heat, and sear sausage on each side. Set aside. To the same pan, add the onions, and cook for two minutes until fragrant. Add garlic and bell pepper, turning heat down to medium, and cook for 3-4 minutes. Add the tomatoes and their juices, and sauté two more minutes.
Add the white beans, water, fish sauce, vinegar, smoked paprika, cumin and salt. Stir and bring to a gentle simmer, and cook 3-4 more minutes.
Add the shrimp and continue simmering until they turn pink and are cooked through, and some of liquid evaporates, just a few more minutes. Add the browned sausage back into the skillet and stir.
Taste, adjust salt. Add chili flakes if you like. Stir in the fresh parsley or cilantro.
Divide among bowls and serve.