The drumstick tree's leaves are its most nutritious part. See Drumstick at Wikipedia. They are particularly rich in Vitamin A, calcium, potassium, protein, apart from several other micronutrients. The leaves are commonly used in Indian recipes, particularly in the south. They are usually used whole or chopped. But one disadvantage is that they tend to clump together.

Recently, my wife Susan Mathius made two dishes which I couldn't find on the Internet: Moringa Paneer and Moringa Soup.

In both cases, the leaves are not used whole but scalded and pureed in a blender in the same way that spinach is used in Palak Paneer.

Here are the recipes.

1. Drumstick Leaf Paneer Curry

Paneer: 200 gms
Drumstick leaves: 2 cups
Onion chopped: 1 medium sized
Green chillies: 2
Garlic: 5 pods
Lime Juice: 2 tablespoons
Oil
Water
Salt

Cut Paneer into cubes and shallow fry it and keep aside.
Boil drumstick leaves in a vessel for few minutes. Add salt. Let it cool for a while. Blend it in a blender and keep aside.

Put oil in vessel. Add chopped onions and fry for 3 minutes.
Add chopped garlic and fry for a minute. Add green chillies and fry for a while.
Add pureed drumstick leaves and let simmer for 2 to 3 minutes. Add fried paneer and salt to it.
Transfer it to a serving bowl and add lime juice.

2. Drumstick Leaf Soup

Drumstick leaves: 2 cups
Tomatoes: 2 medium sized
Garlic: 4 pods
Green chillies: 2
Water: 2 cups
Salt

Boil drumstick leaves with 2 cups of water, garlic and green chillies for few minutes. Add salt and keep aside.
Blanch tomatoes and remove the skin.
Blend the drumstick leaves and the tomatoes in a blender. Heat the pureed drumstick leaves and tomatoes for 3-5 minutes.
Serve hot. Add salt and/or pepper if required.