In large skillet with cover, heat oil over medium-high heat. Add potatoes and onions; salt and pepper to taste. Cook potatoes until they are golden brown, stirring occasionally (about 5-7 minutes).
Stir in curry powder, ginger, garlic and red pepper flakes; cook 1 minute.
Stir in vegetables and tomatoes; bring to a simmer. Simmer, covered, until potatoes are fork tender, stirring occasionally (about 10-15 minutes).