Preheat oven to 400 degrees.
Clean, trim and halve green beans, set aside
Bring a large pot of water to a boil, add 1 Tbs of salt
Add the green beans to the boiling water and blanch for 5 minutes.
While beans cook, prepare a bowl filled with ice water.
Drain the beans, then immediately place into a large bowl filled with ice water to stop the cooking process. Let sit for 1-2 minutes.
Drain again and set aside.
Over medium-high heat, cook bacon in a large ovenproof skillet.
When bacon is crispy, remove from skillet, but leave 1-2 Tbs bacon grease in skillet for cooking mushrooms.
Rough chop the bacon and set aside.
Add the mushrooms to the skillet with the bacon grease, add 1 teaspoon salt and 1 teaspoon pepper.
Cook, stirring occasionally for about 5 minutes until mushrooms start to soften.
Add the garlic, stir, and cook for another 2 minutes.
Sprinkle the flour on top and stir until combined.
Add the chicken broth and simmer for 3 minutes.
Reduce heat to a medium low, and add sage, thyme, and half and half.
Let cook down to thicken, about ten minutes.
Remove from the heat and add the bacon and the green beans.
Stir in the skillet, then top with the french fried onions.
Bake until bubbly, about 10-15 minutes.