Save on cleaning! Start the recipe with a large, non-stick sauté pan that you can cook, bake, and serve the green beans in, without having to mess with a lot of pans!
Preheat oven to 350 degrees. Cook the prepared green beans in boiling water for 5-6 minutes, until bright in color. Drain and place the beans in an ice-water bath (ice and water) to stop the cooking; drain and pat dry.
In a large (oven proof) sauté pan, sauté the bacon and sweet onion in the butter until cooked, for 8 minutes. Add the flour and garlic; gently stir and cook for 1 minute. Gradually whisk in the wine and half-and-half, cooking for another 4 minutes, until thick and bubbly.
Remove from heat and add 1/4 cup Parmesan cheese, Worcestershire sauce, salt and pepper, mixing together; add more salt and pepper according to taste.
In a small sauté pan, heat 2 Tbsp. butter, and sauté the shallots for 3-4 minutes, until crisp. Remove from the pan and place on a paper towel to absorb any grease. Allow to dry for about 5 minutes.
In the same large sauté pan, add the green beans to the sauce, mixing together. Sprinkle with remaining 3 Tbsp. Parmesan cheese, panko breadcrumbs, and fried shallots. Bake for 30 minutes until golden and bubbly. Serve immediately.