Add 50 to 70 ml of coconut milk in the wide thick-bottom pan or kadhai and cook on medium flame till it is reduced and coconut oil starts separating from the coconut milk.
Once you see oil releasing from the milk, add 3 tbsps of Thai red curry paste.
Mix the paste nicely with the coconut oil and cook the curry paste for a couple of minutes in the coconut oil.
After a few minutes, you will notice the oil is separating from the paste, now add the remaining 300ml of coconut milk in the pan.
Mix the paste with the coconut milk without forming any lumps. It will take time to blend the milk with paste.
Now add 1 tsp of soy sauce.
Followed by a tsp of palm sugar or regular sugar.
Lastly, add a tbsp of tomato ketchup and mix all the ingredients nicely.
Once the curry comes to a boil, lower the flame. and add the chopped veggies - courgette, button mushroom and boiled and rinsed bamboo shoots.
Now add ½ tsp of freshly crushed black pepper and salt as per taste. Do not add more salt, Thai curry paste already has salt in it.
Mix the veggies and spices with the curry so that all the veggies are covered from all the sides with curry.
Cover the pan with the lid and cook for 5 to 6 mins.
After 5 to 6 mins, remove the lid and add chopped red bell peppers.
Again cover the lid and cook for another 10 minutes on low-medium flame, so that bell peppers still retain some crunch and bamboo shoots absorb the Thai flavour from the curry.
After 8 to 10 mins, turn off the flame and gently stir the curry and veggies together so that everything is combined well.
Serve the hot Thai red curry with steamed jasmine rice or plain basmati rice.