I've only made this a couple of times and I looked at a lot of different recipes, on the net, in a Tommy Tang book we have, and on the can of curry paste. I found the following in my recipe file, so I think I sort of followed this and the can directions, and improvised.
This printout of this recipe is from a site at www.fbnr.com/Recipes/
It included a recipe for making Masaman curry paste whice I did not print. I'll give you the recipe, then share my ideas.
Masaman Curry Paste (quantity is from recipe, I'd start with 2-3 tbs.)
4 Tbs. oil (I use peanut)
1 medium onion, cut into strips
1 1/2 lbs. boneless beef chuck cut in 1" cubes
2 cans (app. 14 oz. each) coconut milk (not cream of coconut)
3 tbs. fish sauce
2 lbs. boiling potatoes
1 large red bell pepper, cut into strips
1/2 cup roasted, unsalted peanuts, chopped
2 tbs. lime juice
1/4 cup chopped fresh basil or cilantro leaves
1 - Peel potatoes, cut into 1 1/2" cubes. Set aside in cold water
2 - Heat 1 tbs. oil in wok, large skillet over medium-high heat. Add onion. Stir fry until golden then remove to a bowl.
3 - Add 1 tbs. oil, increase heat to high, stir-fry half of beef until brown and remove.
4 - Repeat with remaining beef
5 - Add remaining 1 tbs. of oil, add curry paste and cook, stirring to scrape pan, 2-3 minutes until paste is fragrant. Add coconut milk and fish sauce and stir and scrape bottom of pan.
6 - Return beef to pot and bring to boil. Reduce heat, cover and simmer for 45 minutes.
7 - Add potatoes and onion, cook 20-30 minutes until meat and potatoes are tender. Add red pepper, cook until heated through.
8 - Stir in peanuts and lime juice, sprinkle with basil. Serve over rice.
I usually don't bother with basil in Thai dishes unless I can get Thai basil, at most I'll dust a pinch of dried in the dish for just a hint of flavor.
I think I added carrots, cut in disks, to this. Don't know if it's authentic, but I see plenty of carrots in cheap Thai restaurants. We liked it.
Two cans of coconut milk is a lot. I might think of using one can and adding a cup of broth. BTW - don't bother with "Lite" coconut milk, in looking at the labels I've found they are just the regualr stuff with water added. Also, avoid any product with sweeteners.
Tommy Tang makes his version with lamb and says that's unusual, but I saw several references to lamb masamun curry in my research. Masamun is apparently the Thai word for Muslim and lamb, I understand, is the primary meat in the Muslim world, so it makes sense.
Go ahead and play with this, let us know if you come with with any great inspirations.