1. Combine first 3 ingredients in a large saucepan over medium-high heat; bring to a boil. Cover, reduce heat, and simmer 15 minutes or until liquid is absorbed and rice is tender. Remove pan from heat; let stand 5 minutes. Fluff with a fork.
2. Heat oil and butter in a small skillet over medium-high heat until butter melts. Add mustard seeds to pan; cook 2 minutes or until seeds begin to pop. Scrape seed mixture into rice mixture using a rubber spatula. Add 3 tablespoons cilantro, lemon rind, and lemon juice to rice; stir well. Garnish with cilantro sprigs, if desired.