1 Tbs. canola oil
1 tsp finely chopped garlic
1/2 tsp sambal oelek or other chili paste
1/2 tsp red pepper flakes
3 thin slices fresh ginger
1 stalk lemongrass (white part only)
5 cups low-sodium chicken broth
1 cup coconut milk (stirred well)
2 Tbsp fish sauce
1 1/2 Tbsp brown sugar
zest of one lime
1/2 cup canned straw mushrooms, drained and quartered
2 Roma tomatoes, seeded and chopped
1 lb boneless, skinless chicken breasts, sliced across the grain into thin slices
1/4 cup fresh lime juice
1 green onion, coarsely chopped
6 sprigs fresh cilantro, coarsely chopped
6-7 fresh Thai basil leaves, coarsely chopped
Bruise lemongrass with the side of a knife and cut into 1-inch pieces on the diagonal.
In a saucepan, heat the oil over moderate heat. Add the garlic, chili paste, and red pepper flakes. Stir until fragrant (1 minute). Add the ginger and lemongrass; stir until lightly browned (about 2 minutes). Add the broth and coconut milk and simmer for 5 minutes. Add the chicken and simmer for 10 - 15 minutes.
Bring the soup to a boil. Add the fish sauce, sugar, lime zest, mushrooms and tomatoes, continue to simmer for 2-3 minutes more. Remove pan from the heat and add the lime juice, green onion, basil and cilantro. Serve immediately.
TIP: Chili paste is available at Asian markets and larger grocery stores.