If you have a garden, chances are you'll have a plethora of squash sometime during the summer. Here's a delicious way to prepare some of your seasonal bounty.
Trim the stem ends of the squash and discard. Blanch whole zucchini in boiling salted water until just shy of tender, 3 to 5 minutes. The zucchinis need to be firm enough to maintain their shape when hollowed out. Drain and refresh in ice cold water to stop the cooking process. When cool, drain again, and pat dry.
Cut each zucchini in half lengthwise. With a small spoon, scrape out the flesh and seeds, leaving a 1/4-inch-thick shell wall. If the squash doesn't sit solidly on the counter, shave a small slice from the underside so it doesn't rock.
Melt the butter and sauté shallots for 3 minutes. Add the garlic and mushrooms, and cook on medium high heat, stirring constantly. When the mushrooms have begun to express their moisture, add the white wine and corn, and continue cooking rapidly for another 3 or 4 minutes. Most of the liquid must evaporate.
Transfer mixture to a bowl and add the cheddar, ricotta, and tarragon. Season to taste.
Fill the shells with the vegetable mixture, mounding slightly. Cover with grated parmesan cheese. Transfer to the prepared dish and cover with aluminum foil.
Bake for 10 minutes, then uncover. Bake an additional 10 minutes, or until zucchini are tender and cheese has browned. If squash is tender but cheese isn't golden, run under a broiler to gratinée. Let zucchini rest for 10 minutes before serving.