Heat oven to 350 degrees. Cook green beans in boiling salted water, covered, in a Dutch oven four to five minutes or to desired degree of doneness; drain. Plunge into ice water to stop the cooking process; drain and pat dry.

Sauté mushrooms and onion in melted butter in Dutch oven over medium heat 10 minutes or until golden; whisk in flour and garlic and cook, whisking constantly, one minute. Gradually whisk in wine and cook, whisking constantly, one minute. Whisk in half-and-half and cook, whisking constantly, three to four minutes or until sauce is thickened and bubbly. Remove from heat and whisk in 1/3 cup cheese and next three ingredients.

Fold green beans into sauce. Place in a lightly greased 2 1/2-quart baking dish. Sprinkle remaining Parmesan and panko over green bean mixture. Top with fried shallots.

Bake at 350 degrees for 25 to 30 minutes or until golden and bubbly. Serve immediately.

For the fried shallots: Separate four large, sliced shallots into rings. Toss in all-purpose flour. Pour vegetable oil to depth of one inch in a medium saucepan; heat to 350 degrees F. Fry shallots, in batches, three to four minutes or until crispy and just golden. Drain on paper towels; season with salt and pepper to taste.