Arrange peas and carrot in a vegetable steamer over boiling water. Cover and steam 8 minutes or until vegetables are tender. Set aside.
Combine broth and wine in a medium saucepan; place over medium heat. Bring to a simmer; cover, reduce heat, and maintain a very low simmer.
Saute chopped onion and green onions in margarine and hot olive oil in a medium saucepan over medium-high heat until tender. Add rice, and saute 4 minutes or until rice is translucent. Add 1/2 cup simmering broth mixture to rice mixture; stir constantly until most of the liquid is absorbed. Continue adding broth mixture, 1/2 cup at a time, stirring each time until liquid is absorbed (the entire process should take about 30 minutes). Stir in peas, carrot, 1/4 cup cheese, walnuts, and parsley. Sprinkle with remaining 2 tablespoons Romano cheese; serve immediately.