1. Purèe the onion, garlic, dried shrimp, chiles, and shrimp paste in a blender. Add ½ cup of the oil and process until smooth.

2. Heat 2 tbsp oil in a wok over medium-low heat. Add the onion mixture and cook, stirring often, about 10 minutes, or until relatively dry. Transfer to a bowl.

3. Wipe out the wok. Add 2 tbsp oil and heat over high heat. Add the onion and stir-fry for 1 minute. Add the red and green peppers and stir-fry for 3 minutes. Add the baby corn and stir-fry for 1 minute more, until the vegetables are crisp-tender. Transfer to a plate.

4. Add the remaining 1 tbsp of oil to the wok and heat. Add the fish and shrimp and stir-fry for 2 minutes, or until opaque. Return the onion mixture and vegetables to the wok and stir-fry about 1 minute. Serve hot.