Preheat oven to 375 degrees Fahrenheit (190 degrees Celsius) and lightly grease a 9x5 inch loaf pan.
Heat olive oil in a skillet over medium-high heat. Add mushrooms and onions; sauté until moisture has evaporated and vegetables are softened, about 8 minutes. Add garlic and cook for 1 minute more. Remove from heat and cool slightly.
In a large mixing bowl, combine ground chicken, sautéed mushroom mixture, panko breadcrumbs, beaten egg, Worcestershire sauce, thyme, salt, pepper, and 1 cup of the shredded Swiss cheese.
Gently mix ingredients until just combined, taking care not to overwork the meat.
Transfer the mixture to the prepared loaf pan and shape into an even loaf.
Bake for 45 minutes, or until the internal temperature reaches 165 degrees Fahrenheit (74 degrees Celsius).
Sprinkle the remaining 0.5 cup of Swiss cheese over the top and bake for an additional 5 minutes until melted and bubbly.
Allow the meatloaf to rest for 10 minutes before slicing and serving.