12 med. tomatoes
1 1/2 tsp. salt
1 1/2 tsp. sugar
3 (10 oz.) pkg. frozen chopped spinach
1 med. onion, chopped
1/3 c. butter, melted
3 tbsp. all purpose flour
1 1/2 c. milk
3/4 tsp. salt
1/2 tsp. white pepper

Cut top quarter off each tomato. Scoop out pulp, leaving shells intact; reserve pulp for other uses. Sprinkle inside of each tomato shell with 1/8 teaspoon salt and 1/8 teaspoon sugar and invert on paper towels to drain.

Cook spinach according to package directions. Drain well by pressing out excess liquid with back of spoon. Saute onion in butter in a heavy saucepan until tender. Add flour, stirring until blended. Cook 1 minute, stirring constantly. Gradually add milk; cook over medium heat, stirring constantly, until mixture is thickened and bubbly. Stir in spinach, 3/4 teaspoon salt and pepper.

Spoon mixture into shells and place in a greased 13 x 9 x 2 inch baking dish. Bake at 350 degrees for 20 minutes or until heated. Yield 12 servings.

To Make Ahead: Prepare tomatoes as directed, but do not bake. Cover and chill up to 24 hours. Remove from refrigerator; let stand 30 minutes. Bake as directed.