Preheat oven to 350°F Lightly grease an 8x8x2" baking dish with solid vegetable shortening or butter. Using a stiff brush, scrub zucchini well under cold running water. Trim off nd discard stem ends; cut zucchini crosswise into 1/4" thick slices.

In a medium-sized bowl, mix flour with 1/2 teaspoons of the salt, 1/2 teaspoons of the dried oregano leaves and 1/8 teaspoons of the pepper. Add zucchini slices and toss thoroughly to coat all sides with the seasoned flour mixture.

Place olive oil in a large, heavy skillet and heat over moderately high heat until very hot. Add zucchini, a few slices at a time, in a single layer. Saute for about 4 min., or until well browned. Turn slices over and brown second side.

As zucchini slices are done, remove and drain on paper towels. Repeat with remaining slices until all are browned. Arrange slices in the prepared baking dish; top with tomato slices. At this point you may cover and chill casserole until ready to bake.

Thoroughly blend with a wire whisk or small spoon sour cream, 1 teaspoons of the salt, 1 teaspoons of the oregano leaves and 1/8 teaspoons pepper in a small bowl. Spread this cream mixture evenly over zucchini and tomato slices in casserole. Sprinkle with grated cheese.

Put zucchini casserole on the center rack in oven and bake for 30-35 minute or until cheese is melted and lightly browned and the zucchini and tomatoes are tender. Remove from oven and serve immediately. Makes 6 servings.