Prepare the masala ingredients by heating the oil. Add peanuts, cumin seeds, coriander seeds, fenugreek seeds and red chili peppers to the pan and saute until the peanuts are a couple of shades darker.
Place the ingredients in a blender, add the ginger garlic paste, jaggery, turmeric and coconut milk and process into a coarse paste. It should clump together when you press it in your fist, which will make stuffing the eggplants easier.
Divide the stuffing equally into eight portions and stuff between the petals of each eggplant. Set aside.
Heat the oil in a pressure cooker over medium-high heat.
Add the potatoes and stir-fry for a couple of minutes or until they start to color slightly.
Add the eggplants one by one-- place them in a single layer, if possible.
Add ¾ cup of water to the pressure cooker and sprinkle on some salt for taste (not too much, because there's already salt in the stuffing, but you want a little something for the potatoes).
Stir the contents of the pressure cooker gently so everything looks well-distributed.
Click on the pressure cooker lid. My pressure cooker is different from the typical Indian ones that come with a "whistle" that goes off when it reaches pressure. It has a little button that pops up when the cooker reaches pressure. Once it did, I lowered the heat let the eggplant cook for another 10 minutes. If you have the cooker with the whistle, you might need to go through a couple more whistles to get the same result.
Once the steam inside the pressure cooker has dissipated, open the pressure cooker and garnish the eggplant, if you like, with some coriander.
Serve hot with dal.