This is a flexible dish you can make as mild or as spicy as you fancy. My recipe uses beef, but I have had equal success using chicken and even prawns. Or you can omit the protein altogether for a tasty vegetarian option.
Mix the beef strips with the diced garlic and 2 tsp of oil. Marinade in the fridge for at least half an hour (a couple of hours is fine).
Heat 2tbs of oil in a wok on medium and add the capsicum. Stir fry for a couple of minutes then add the zucchini and finally the mushrooms. Continue to fry until cooked but slightly crunchy (a sprinkling of cold water while frying will help to cook the vegetables evenly). Remove the vegetables from the wok (set aside in a large bowl) and wipe the wok clean if necessary.
Reheat the wok on high and add 1tbs of oil. When hot quickly stir fry beef strips for about two minutes but no longer. Remove from the wok and add to the bowl of cooked vegetables.
Place the wok back onto a medium heat then add the curry paste, fish sauce and sugar. Stir the curry mixture quickly to combine then return the meat and the vegetables to the wok. Toss for 1 minute only to reheat ( try not to over cook the beef strips as they will become tough). Add enough coconut milk to just cover the stir fry.
When the milk comes to the boil, turn off the heat immediately. Add the basil and spinach leaves and stir until the leaves wilt.