Use a pressure cooker with separators. In one compartment, place the rehydrated peas with just enough water to cover.
Halve the tomatoes and place in another compartment. No water required in this.
You can cook rice in the third compartment if you want to serve this curry with rice. Pressure cook for 2 whistles and keep on sim for 5-7 minutes and remove from flame. Open when cool enough.
The peas should be cooked to very soft but maintain their shape. Tug off the tomato skins, mash with fingers and keep aside.
In a large kadai, heat 1 tbsp oil, add 1 tsp cumin seeds, fat pinch of asafoetida. Once the cumin splutters, add the ground paste to the oil and fry on medium flame for around 5 minutes, until oil separates and the onion and garlic is cooked off.
To the cooked paste, add the cooked black eyed peas and the mashed tomatoes. Add turmeric, salt and garam masala powder. Bring to a simmer. Add some water if it is too dry. Let this simmer for 2 minutes. Remove from flame and add fresh coriander.