Smash the mushrooms under the bottom or a large skillet until broken into ¼ or ½ inch pieces. Roughly chop into ⅛ to ⅛ inch pieces. Set aside

Combine the soy sauce, lemon juice, chicken stock, and cream in a 1 quart liquid measure or medium bowl. Set aside.

Heat the shallot oil and butter in 12-inch nonstick skillet over high heat until the butter melts and the foaming subsides. Add the mushrooms and cook, stirring occasionally, until their liquid has evaporated and the mushrooms begin to sizzle, 6 to 10 minutes. Reduce the heat to medium-high, add the garlic and cook, stirring until fragrant about 30 seconds. Add the flour and cook, stirring constantly, until light golden blonde, 1 to 2 minutes. Whisking constantly, add the stock and cream mixture. Bring to a boil, whisking, then reduce to a simmer, and cook, whisking, until the mixture has a consistency somewhere between pancake batter an dheavy cream, about 5 minutes. Season to taste with salt and pepper. Set aside.

Adjust an oven rack to the lower middle position and pre-heat the oven to 350 F. Bring 4 quartz water and ¼ cup kosher salt to boil in a Dutch oven over high heat. Fill a large bowl with 4 cups ice cubs and 2 quarts qater. Add the green beans to the boiling water an cook until tender but still green, about 7 minutes. Drain and immediately transfer to the ice water to cool completely. Drain well.

Combine the green beans, mushroom sauce, and 1 cup of the fried shallots in a bowl. Transfer to a 9-by-13-inch casserole or 10-by-14-inch oval casserole. Bake until hot and bubbly, 15 to 20 minutes. Top with the remaining fried shallots and serve.