Have a bowl of ice water ready.

 

In a small saucepan of boiling water blanch cilantro and parsley 10 seconds and drain in a sieve. Refresh herbs in ice water and drain in sieve. Chop shallots and garlic.

 

In a small nonstick skillet cook shallots, garlic, gingerroot, cumin, and red pepper flakes in 1 Tbsp water and oil over moderately low heat, stirring, until shallots are softened.

 

In a blender purée shallot mixture, herbs, remaining 1/4 cup water, and soy sauce until smooth, about 1 minute. Season with salt and pepper. Sauce may be made 1 day ahead and chilled, covered.

 

Bring sauce to room temperature before serving. Just before serving, stir in lemon juice.

 

Makes about 3/4 cup.