In a pressure cooker, heat 1 tbsp of mustard oil and fry one medium-sized, finely chopped onion along with 1 tsp of cumin seeds and 2 pinches of asafetida (hing) on a medium flame until the onions turn slightly brown. Then add 1 piece of bay leaf and 1 piece of cinnamon (1 inch stick) until the onion turns further brown. (Pro tip: Onions should be fried brown to achieve a nice red color of the dish).
Now mix 1 tsp of ginger garlic paste followed by 1 piece of tomato (large size, finely chopped) nicely until the tomatoes become soft.
Then add 3 pieces of roughly chopped green chilies, salt to taste, 1 tsp of Kashmiri red chili powder, ½ tsp of turmeric powder, and 2 tsp of coriander powder and fry them nicely for about 2 minutes. Add 300 grams peeled, washed, and roughly sliced tinda and cook nicely for about 3 to 4 minutes on a medium flame.
When the oil separates, add ¼ cup of water. Mix nicely and pressure cook for up to 2 whistles on a medium flame. (Pro tip: Do not add a lot of water because apple gourd releases water itself).
Mash and mix a few pieces with a spatula. Finally, mix 1 tsp of garam masala and a handful of finely chopped fresh coriander leaves. (Pro tip: I prefer mashing a few pieces of tinda as it gives a nice thick consistency to the final dish).
Give it a final stir. Your tasty and healthy homemade tinda curry is ready. Transfer it to a serving bowl and enjoy hot.