In a bowl, add in the buttermilk, and toss in sliced red onion. Coat the onions, and place them in the fridge for at least 15 minutes to rest.

In another small bowl, whisk together flour, panko, and dried mixed herbs.

In a dutch oven, heat vegetable oil until it is shimmering. Toss in a pinch of panko mixture and if it starts to bubble and fry, you’re ready to go.

Dredge red onions straight from the buttermilk, and toss into the flour/panko mixture. Gently drop in the coated onions into the hot oil and allow to fry until deep golden brown.

Remove from the oil and place on a paper towel lined baking sheet to drain.

Preheat oven to 375 degrees.

In a large pot, bring salted water to a boil. Trim the green beans and place into the pot of boiling water. Boil for about 5-6 minutes until just tender, but still slightly crisp.

Drain and rinse with cold water to stop the cooking process. Set aside.

Melt the butter in a large skillet, and add in the mushrooms. Season with salt and allow to soften and become tender.

Add in the garlic and thyme. Sprinkle in the flour and stir until it coats mushrooms. Stir in the half and half and the chicken broth. Bring the mixture to a simmer and allow the sauce to thicken.

Stir in the parmesan cheese, and green beans. Lastly add in the flaked smoked salmon, and fold in.

Transfer the whole mixture to a large casserole dish, top with fried onions, and place in the oven to bake for 15-20 minutes.

Serve hot.