Slice zucchini into 1/2" rounds. Blanch zucchini in boiling water for 4 minutes. Drain well, and pat dry. Slice tomatoes, lengthwise, into 4 slices per tomato. With a spoon remove seeds. In a greased 9x9 glass baking dish, place zucchini, overlapping, in a single layer to cover bottom of dish. Drizzle zucchini with 1 tbsp of olive oil over top. Sprinkle with with garlic, thyme, salt and pepper. Next add a layer of crumbled feta. Top dish with tomato slices. Sprinkle with salt and pepper. Drizzle all of casserole with remaining oil. Bake, in preheated, 400degreesF oven for 40 minutes. Remove and let rest 10 minutes before serving.