Put the butter in a dish and cook for 45 seconds. Add the onion and garlic and cook, covered, for 3 minutes.
Add the black-eyed beans (peas), tomatoes and ginger and cook, covered, for 4 - 5 minutes until heated through, stirring once.
Season to taste with salt, pepper and garam masala and stir in plenty of chopped coriander (cilantro) leaves. Eat hot with rice.
This dish is also delicious cold.