Combine water, rice, and salt 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.
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 tbs cilantro, lemon rind, and lemon juice to
rice; stir well. Garnish with cilantro sprigs, if desired.