Drain and chop tomatoes, reserving 1/2 cup liquid; set aside.
Heat olive oil in a large skillet; add flour, stirring until smooth. Gradually add reserved tomato liquid; cook over medium heat 2 minutes, stirring constantly. Add reserved tomatoes; continue cooking, stirring constantly, until mixture is thickened and bubbly. Stir in cheese, and salt and pepper; mix well.
Cook vermicelli according to package directions; drain. Combine tomato mixture and vermicelli, mixing well. Beat egg yolks in a medium mixing bowl until thick and lemon colored. Gradually stir one-fourth vermicelli mixture into yolks; add to remaining mixture, stirring well.
Beat egg whites (at room temperature) until stiff but not dry. Fold into vermicelli mixture; spoon into a lightly greased 1 1/2- quart casserole. Bake at 350° for 10 minutes. Serve immediately.