Herb Tomato Tart
["3 Tbsp. butter", "2 c. onions, thinly sliced", "1 Tbsp. flour", "2 large eggs", "1 c. milk", "1 tsp. salt", "1/8 tsp. pepper", "2 Tbsp. chopped fresh parsley", "1 Tbsp. chopped chives", "1 1/2 tsp. tarragon", "1 1/2 tsp. fresh basil", "4 oz. shredded Cheddar cheese (1 c.)", "1 tomato, thinly sliced", "1 (9-inch) crust (deep dish)"]
["Preheat oven to 425\u00b0.", "Melt butter in skillet. Add onions and saute until tender, 5 to 10 minutes.", "Stir in flour; set aside. Beat eggs and milk. Add salt, pepper and herbs. Place onions and cheese into pie crust. Cover with egg mixture. Bake 15 minutes. Reduce heat to 350\u00b0. Bake 15 minutes. Arrange tomato slices on top and return to oven for 10 minutes."]
["butter", "onions", "flour", "eggs", "milk", "salt", "pepper", "parsley", "chives", "tarragon", "fresh basil", "Cheddar cheese", "tomato", "crust"]