Cut bell pepper into short strips. Cut carrot, spring onion und zucchini into slices. In a bowl, stir coconut milk until you have a smooth consistency.
In a small pot, warm olive oil over medium heat. Saute curry paste for 1 minute while stirring. Whisk in half of the coconut milk until combined and cook for 5 minutes. Stir occasionally.
Mix together the rest of the coconut milk, water, salt, soy sauce and sugar. Add to the pot and let simmer for 10 minutes.After that, add bell pepper, carrot, spring onion and zucchini and mix together. Let cook for another 5 minutes.