Drain sardines from tomato sauce, reserving sauce.
In a wide pan over medium heat, heat oil. Add potatoes and cook until lightly browned and almost cooked through. Using a slotted spoon, remove from pan and drain on paper towels.
Add carrots and cook until almost cooked through. Using a slotted spoon, remove from pan and drain on paper towels.
Remove excess oil except for about 1 tablespoon. Add bell peppers and cook for about 20 to 30 seconds. Using a slotted spoon, remove from pan and drain on paper towels.
Add onions and garlic and cook until softened.
Add chili peppers.
Add reserved sardines sauce and water. Bring to a boil, stirring to distribute .
Add potatoes, carrots, and olives. Season with salt and pepper to taste. Cook until potatoes and carrots are tender.
Add sardines and bell peppers. Gently stir to distribute.
Continue to cook until heated through. Serve hot.