Heat oil in a 3-quart non-reactive saucepan over medium high heat, add the onions and cook until browned and softened, about 8 to 10 minutes. Add the garlic, tomatoes, chicken broth, potatoes, pepper flakes, and salt, stir until combined. Cover and reduce heat to medium and cook 45 minutes or until potatoes are almost mushy but have not lost their shape.
Pour half the potatoes and tomatoes in a refrigerator dish for tomorrow night's quick vegetable beef stew. Lay cod over stew, cover and steam until tender and fish begins to flake, 5 to 7 minutes. Serve immediately.
Vegetable Beef Stew Morph:
In a large soup pot, heat olive oil over medium high heat, add stew meat, and cook until browned on all sides, about 3 to 5 minutes. Add leftover potatoes and tomatoes, chicken stock, green beans and corn. Cook until vegetables are done, about 6 to 8 minutes. Taste and adjust seasonings. Serve immediately.
Use any veggies you can get your hands on, frozen corn, green beans and peas are fine. Anything you have hanging around, if they're already cooked, the cooking time is cut back.