Heat oil in large saucepan and then sauté onions, garlic and ginger until
onions are soft and golden.
Add cumin, turmeric, salt and red pepper, then
tomatoes and lightly chopped coriander leaves. Cook briskly, while stirring for about five
minutes. Add potatoes, water, and/or juice. Reduce to a steady simmer and
cook 45-60 minutes until potatoes are tender. Add frozen peas 15
minutes before completion of cooking.
Garnish with fresh coriander leaves and add garam
masala to taste.