Chop onion finely and peel and chop tomatoes. Heat some oil and fry onion for three minutes. Crush the garlic and finely mince the ginger and add to the onions and fry for two minutes. Put in meat and fry till dry and brown. Add tomatoes, spices, peas, salt and a little water and simmer for 20 minutes until all the liquid has been absorbed and the peas and meat are tender.