They say the devil is in the details. As much as one hates it, the key to an authentic and delicious curry is not the spices, but the fine and specific way that the vegetables are chopped and prepared. When I used to work for a botox company years ago I worked with a Thai lady who taught me all about Thai food.
Most Thai households will use one of the excellent curry pastes that are available. There are several different varieties, but remember to read labels if you are aiming for a vegetarian curry. Keoh Wan Green Curry Paste doesn’t contain shrimp paste and is available from online grocers if you don’t have a local Asian Grocer.
It is important to remember to choose a curry paste and not an already mixed sauce this is what will give you an authentic taste. Most jars will give details of a recipe on the back cover. It is roughly 50 grams of curry paste, sauteed until fragrant, and add 400 ml of coconut milk, fish sauce and palm sugar to taste. You can substitute a light thin soy sauce for the fish sauce or buy a vegetarian fish sauce which will provide more refined and subtle taste. To begin, you should prepare your vegetables a small handful of each item per person:

1. carrots about one half to one third of a carrot person sliced into thin batons, the length of your middle finger and about half the width of a pencil
2. red peppers finely sliced and approximately the same length
3. spring onions sliced thinly and again a similar length
4. mange tout , bamboo shoots, fresh peas
5. thin strips of baked or fried tofu

In a hot wok with a thin coating of peanut oil add your spring onions, followed by carrots and red peppers, finally the mange tout and fresh peas. Add 50 grams of curry paste to coat all of the vegetables then add the coconut milk. Simmer gently until the vegetables are tender. Add the tofu fish sauce and sugar to taste. Serve to Thai rice or noodles.