Heat sufficient oil in a kadai.
Take shrimps in a bowl. Add salt, ½ tablespoon chilli flakes, chopped garlic and cornstarch and mix well.
Deep-fry the shrimps till golden and crisp. Drain on absorbent paper.
Slice the garlic cloves and spring onion bulbs thinly.
Heat 2 tablespoons oil in a non-stick pan. Add sliced garlic, mix and sauté till golden. Add sliced spring onion bulbs, mix and sauté for a minute.
Add sweet chilli sauce and remaining chilli flakes and mix well.Add fried shrimps and toss to mix.Add peanuts and mix well.
Cut spring onion greens, add to the pan and toss to mix. Switch off heat, add lemon juice and mix well.
Spread iceberg lettuce leaves on a serving plate and put the prepared shrimps on them.
Serve hot garnished with yellow and red bell pepper curls and coriander sprigs.