Make two diagonal slits like an X (pictured above) in each eggplant (SEE NOTES)
Rub a generous amount of olive oil on the eggplants, getting it inside all the crevices
Air fry for 20 minutes, turning them around every 5-10 minutes(SEE NOTES)
While the eggplant is cooking, heat the cooking oil and saute the garlic in it for about 30 seconds
Add the Thai chillies and saute them for 10-15 seconds
Slice the tomatoes and saute them just till they start wilting
Add the salt, red chilies and turmeric and stir
Add the air fried egg plants, cover and cook on the lowest setting of your stove for 5 minutes
Uncover and turn the flame on high to dry any residual liquid (SEE NOTES)
Turn your stove off, sprinkle the amchur powder (and stir in the tamarind if adding) and cilantro, gently stir and serve
Notes
COOKING OIL I alternate between avocado oil and olive oil for most of my cooking. Avocado oil has a higher smoke point so is better to use when cooking a curry as the prolonged cooking time makes it a better option. But feel free to use anything you prefer.
CUTTING THE EGGPLANT Indian eggplants are tiny so I like to make these diagonal cuts and preserve the whole eggplant as it makes for beautiful presentation. If you're using a large eggplant then I would cut large semicircular slices, about ½ inch in thickness, with the skin on.
AIR FRYING YOUR EGGPLANT Air Fryers vary from one to another, I own a Cuisinart Air Fryer Toaster Oven. If yours is different you may need to adjust cooking times or temperature a little bit. If you don't have an air fryer I would bake my eggplant in the oven at 400 degrees for 25-30 minutes.
DON'T STIR Avoid stirring too much after the air fried eggplants are added to the curry. This will cause them to dissolve and get mushy, ruining the consistency of the curry.
AMCHUR POWDER Always add the Amchur powder at the end. This is a dried mango powder and great for flavor but if it's cooked it loses its pungency.
TAMARIND Although I don't always find it necessary in this recipe, about 2 tablespoons of tamarind at the end are an add in option that you may like.