In a small saute pan heat 1 teaspoon olive oil.
Cook onions over medium heat until caramelized.
After the onions are caramelized coat them with Panko crumbs.
Place coated onions on a baking sheet.
Brown in a 350 degree F oven for 5-10 minutes, until crisp.
In a large saute pan heat 1 teaspoon olive oil.
Cook garlic over medium heat for 1-2 minutes.
Add mushrooms cooking for 3-5 minutes.
Season with salt, pepper, and thyme.
Add vegetable broth and Worcestershire sauce, bring to a simmer.
Slowly whisk in milk and continue to a slow boil.
Whisk in flour slowly, simmering until sauce is thickened.
Toss in green beans.
Place green bean mixture into a baking pan.
Place in a 350-degree oven until casserole is heated through, approximately 20 minutes.
Add crisp onion for the last 5 minutes of cooking.