Cut turkey berries into halves.

Heat oil in a pan. Add cumin seeds and let sizzle for a few seconds. Add onions. Cook until the onions soften.

Add tomatoes and cook until they are mashable.

Add turmeric, black pepper, red chili powder, and green chilies. Cook about 30 seconds, until they are nice and fragrant.

Add potatoes, turkey berries, and salt. Stir to coat the vegetables with the spices. After about 5 minutes, cover with a pan and add water to the pan, or add some water directly to the vegetables and cover with a normal lid. Cook until the potatoes are nice and soft, stirring occasionally to prevent sticking.

Remove the lid, add the garam masala. Stir and remove from heat.