1In small bowl, beat dressing ingredients with wire whisk until smooth; set aside.
2In 1-quart saucepan, heat water to boiling over high heat. Stir in rice. Heat to boiling. Reduce heat to low; cover and simmer 5 minutes. Remove from heat. Let stand covered 5 minutes. Fluff with fork; cool slightly.
3In large bowl, toss rice, carrots, peas and onions with dressing. Let stand at room temperature at least 10 minutes to blend flavors.