In a pot over medium heat, heat 1/4 cup canola oil.
Add potatoes. Cook until lightly browned. Remove from the pan and drain on paper towels.
Add carrots and cook until lightly browned. Remove from the pan and drain on paper towels.
Remove excess oil except for about 2 tablespoons. Add beef. Cook until lightly browned.
Add onions, garlic, and ginger. Cook until softened.
Add fish sauce and continue to cook for about 2 to 3 minutes.
Add water and bring to a boil, skimming scum that floats on top.
Lower heat, cover, and simmer for about 1 to 1 1/2 hours or until beef is tender.
Add coconut milk. Simmer until liquid is slightly reduced.
Add potatoes and carros. Cook for about 3 to 5 minutes or until tender.
Add curry powder. Continue to cook for about 3 to 5 minutes or until sauce is thickened.
Season with salt and pepper to taste.
Add red and green bell peppers. Cook for 1 minute or until tender yet crisp.
Serve hot.