To make the peanut dip, bring the water to the boil in a small saucepan. Stir in the peanut butter, garlic, ginger, spring onion, sugar, soya sauce and chilli powder. Simmer 2 minutes. Remove from heat. Stir in lemon juice. Set aside to cool slightly or refrigerate until ready to serve.
In a large saucepan with a steamer basket, bring water to the boil. Fill a bowl with ice water. Steam carrots for 3 minutes, lift out and plunge into ice water to cool. Steam capsicum for 1 minute, lift out and plunge into ice water to cool. Steam snow peas or beans for 2 minutes, lift out and plunge into ice water to cool. Drain vegetables and dry with paper towels.
Spoon peanut dip into a small bowl and place on a serving platter. Arrange the carrot sticks, capsicum, snow peas or green beans around the bowl. Add the radish as a garnish.