Heat oil in saucepan, add onions and cook over medium heat until softened. Stir in garlic, lemon grass and ginger until aromatic — about 1 minute. Add the curry paste and stir. Pour in 1/2 of the chicken broth and stir until curry paste is dissolved, add the rest of the broth along with soy sauce and sugar. Let it simmer for 20 minutes, covered.
Stir in the noodles, coconut milk, shrimp(or chicken), and lime juice. Cook until shrimp is pink and done. Stir in cilantro, mushrooms and spinach until softened.
Makes 4-6 servings