I’ve never tried to make Thai food from scratch - I always opt for the pre-made curry paste. I was recently challenged by a friend to recreate Penang Red Curry and I obliged since I cannot turn down a cooking challenge. As it turns out making curry paste from scratch is not that difficult. You should be able to find all the ingredients at your local Asian grocer - in my case I went to the Asian Market. There are a few strange items on the list but nothing the shop keeper can’t help you find. Essentially you purchase a bunch of strange ingredients and pop it in a food processor. The peppers provide some spice (I only used two or three) and tomato paste actually provides the red hue.
I didn’t know shallots were a South East Asian ingredient - I think of shallots as Italian - but they even had them at the Asian Market so there you have it - below is the shallots, galangal (similar to ginger) and lemon grass chopped up and ready for the food processor. The lemon grass is quite woody so it takes quite a while in the food processor. Try to chop it as finely as possible before putting it in the processor and don’t add too much coconut milk since that will make the processor less effective - you do need just enough coconut milk to make the blades turn easily though! I learned this the hard way and almost blew the motor once. The alternative would be to buy frozen pre-chopped lemon grass which I will most likely do next time.
Here’s the finished product with a bit of chopped basil added at the end served over brown rice (I would make it with white rice next time). Usually you would use shrimp paste in this recipe but since my roommate is allergic to shrimp I opted out of the shrimp paste.