Bring a large pot of water to a boil. Add the pasta and cook to al dente according to the package directions. Drain into a colander and return it to the pot. Toss with a dash of olive oil to prevent sticking.
Coat the bottom of a large skillet with 1 tablespoon of olive oil and place it over medium heat. When the oil is hot, add the mushrooms. Cook them for about 5 minutes, until browned on the bottoms, then flip and cook about 5 minutes more, until browned on the opposite sides. Transfer the mushrooms to a plate.
Add the remaining tablespoon of oil to the skillet. Once the oil is hot, add the artichoke hearts. Cook the for about 5 minutes, until they begin to brown. Return the mushrooms to the pot, then sprinkle in the flour, flipping the veggies until they're coated with flour. Drizzle in the Cashewmilk while stirring, then stir in the pesto, miso, and lemon juice, stirring well to fully dissolve the miso.
Bring the mixture to a simmer and allow to cook for about 5 minutes, stirring occasionally, until the sauce thickens up and the mushrooms are tender.
Stir in the peas and pasta and allow to cook just a minute more, until heated throughout. Remove the skillet from the heat and season with salt and pepper to taste.
Divide onto plates and top with basil and red pepper flakes. Serve.
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