Take the cashews, place them in a medium sized bowl, and cover them with water until they are completely submerged. Cover with plastic wrap and refrigerate for 8 hours or overnight. Once the cashews have soaked, drain them and rinse thoroughly. Place the cashews in a blender or food processor and add 1/2 cup of water. Process on high speed until pureed into a thick cream consistency.
Line a baking sheet with a double layer of paper towels. Place the slices in a medium bowl and sprinkle the almond meal, arrowroot flour, ground pepper, and salt over the shallots. Toss to evenly coat the shallots. Heat 3 tablespoons of oil in a large sauté pan or skillet on high. Once the oil starts to shimmer (but before it starts to smoke) reduce the heat slightly to medium high and add the coated shallots and fry them, stirring constantly, until they are golden brown, about five minutes or so. Once they are golden brown, move them to the baking sheet.
Add 2 more tablespoons of oil to the sauté pan or skillet and turn to medium heat. Add the sliced mushrooms and cook, stirring frequently, until they are brown, about 5-7 minutes depending on how thick the mushrooms are. Pour the mushrooms and any accumulated liquid, into a heatproof bowl.
Add the final 2 tablespoons of oil to the sauté pan or skillet and turn the heat to medium. Add the onions and cook until they soften about 2-3 minutes. Add the garlic and cook until fragrant, about 30 seconds. Add the green beans, thyme, bay leaves, pureed cashews and vegetable stock. Cook, stirring frequently, until the beans are slightly tender but crisp in the center, about 5 minutes. Add the mushrooms and liquid and continue to cook for another 5 minutes, or until the green beans are tender and the sauce has thickened. Once done, season with salt and pepper to taste. Remove the thyme and bay leaves before plating and sprinkle the fried shallots over the green beans before serving.