1Melt margarine in 10-inch nonstick skillet over medium heat. Cook rice, mushrooms and onions in margarine about 3 minutes, stirring occasionally, until onions are tender. Stir in water, salt and pepper. Heat to boiling, stirring occasionally; reduce heat.
2Cover and simmer about 50 minutes or until rice is tender; drain if necessary. Stir in vegetables and lemon juice. Heat uncovered, stirring occasionally, until hot.