1 red onion
1 cup buttermilk
2 cups flour
1 oz. olive or vegetable oil for frying
Salt and freshly ground black pepper to taste
2 cups milk plus more as needed
1 head cauliflower, cored and broken into florets
1 Tbsp. freshly chopped herbs (such as parsley, rosemary, thyme and sage)
½ lb. butter, softened, plus more for sauteeing
2 4-oz. boneless Missouri trout filets, split, cleaned and deboned
1 cup cornmeal fish breading
¼ cup sliced shallots
1 lb. fresh green beans
½ cup pork jus or chicken stock
Special equipment: candy thermometer
1 DAY AHEAD:
• Using a mandolin, shave the onion into paper-thin rings. Transfer to a bowl with a lid and pour in the buttermilk. Let soak in the refrigerator overnight.
• Preheat the oven to 400 degrees.
• Drain the onion rings well but don’t rinse them. Dredge them in the flour, shaking off any excess.
• Heat the oil in a pot big enough for deep-frying all of the onions at once and clip a candy thermometer to the side. When the oil reaches 350 degrees, drop the onions in and fry until golden brown, about 1 minute. Transfer to a stack of paper towels to drain, and immediately season to taste with salt and pepper. Keep warm.
• Add 2 cups of milk and the cauliflower to a large pot. Bring to a boil, then reduce heat to a simmer. Let simmer until the cauliflower is very tender, about 30 to 45 minutes. Strain, reserving the simmering liquid. Add the cauliflower to the bowl of a food processor and add a few tablespoons of the reserved milk. Blend, adding more milk, a few tablespoons at a time (up to ½ cup), until the mixture is the consistency of thin mashed potatoes. Season to taste with salt and pepper. Reserve and keep hot.
• In a medium-size bowl, stir the freshly chopped herbs into ½ pound of softened butter until thoroughly combined. Season to taste with salt and pepper. Keep soft.
• Season the trout lightly with salt and place the cornmeal breading in a large, shallow bowl. Dredge the fillets in the cornmeal breading. Melt 1 to 2 tablespoons of butter in a large ovenproof saute pan over high heat.
• Working in batches if necessary, add the breaded fish, skin side up, and let cook for 1 minute. Transfer to the oven and bake for 3 minutes. Flip and bake until crisp on the other side, about 2 minutes. Remove from the oven, transfer to a stack of paper towels to drain and keep warm. Add more butter as needed with each batch.
• Meanwhile, heat 1 tablespoon of butter in a skillet and add the shallots. Cook for 1 minute, then add the green beans, and season with salt and pepper. Add the pork jus or chicken stock and continue cooking until the green beans are tender, about 3 to 5 minutes.
• Spread 2 ounces of the cauliflower purée on each of 2 plates (Reserve the remaining purée to use as a side dish with meat or fish entrees.). Top each plate with 2 trout filets. Gently spoon the green beans atop the fish, followed by a spoonful of herb butter. Garnish with a small handful of fried onion rings.