1. Using the back of your chef’s knife, hit the lemongrass stock on a cutting board to bruise it. This will help to release the flavourful oils. Roughly chop.
2. Heat a saucepan over medium heat. Add coconut milk, lemongrass, galangal, lime leaves, fish sauce, salt. Let simmer and infuse for 10 minutes. Turn off heat and add Thai basil and cilantro stems, let steep for 5 minutes, strain.
3. Pour mixture into a loaf pan and cover tightly with plastic wrap. Place in freezer for minimum 1.5 hours until frozen (can do day ahead).
1. Peel prawns, cut into thirds, set aside.
2. In a small bowl mix lemon zest and juice, lime juice, shallot, fish sauce and salt. Stir until combined. Add corn and shrimp.
3. Let sit for 30 minutes (if spot prawns are large, let sit up to 40 minutes).
4. Prepare garnishes; Thinly slice radishes, quarter tomatoes.
Whisk together tomato juice, water and all-purpose flour until smooth. Heat saucepan over medium-low heat. Add 1 Tbsp oil to pan. Being careful to avoid hot spatter, pour half the batter into the pan. Cook until crispy. Remove to drain on paper towel. Repeat with remaining oil and batter.
1. Using a fork, scrape granita into snow. Keep in freezer.
2. Spoon spot prawn ceviche around outside of plate.
3. Garnish with herbs, radish, and sliced chili.
4. Remove granita from freezer and stir in chopped cilantro. Spoon granita into centre of ceviche on each plate.
5. Top each with half piece of tomato tuile.