In a large saucepan, heat broth and keep warm. In a large skillet, saute onion in 2 tablespoons butter and oil for 2-3 minutes or until tender. Add rice; cook and stir for 2-3 minutes. Reduce heat; stir in wine and lemon juice. Cook and stir until all of the liquid is absorbed.
Add heated broth, 1/2 cup at a time, stirring constantly. Allow the liquid to absorb between additions. Cook just until risotto is creamy and rice is almost tender. (Cooking time is about 20 minutes.) Add the lemon zest, salt, pepper and remaining butter; cook and stir until heated through. Transfer to a 15x10x1-in. baking pan. Cool to room temperature. Cover and refrigerate for 1 hour.
Place flour and eggs in separate shallow bowls. Place bread crumbs in another shallow bowl. Shape risotto mixture into 1-1/2 in. balls. Dip fritters in the flour, eggs, then bread crumbs.
In an electric skillet or deep fryer, heat oil to 375°. Fry fritters, a few at a time, until golden brown on both sides.
In a small bowl, combine sauce ingredients; serve with fritters.