Bring mushrooms and water to a boil in a small saucepan over high heat. Cover the pan and remove from the heat; let stand until the mushrooms are softened, about 10 minutes. Line a fine-mesh sieve with a wet paper towel and place over a large measuring cup or medium bowl. Pour the mushrooms and liquid into the sieve. Reserve the liquid. Transfer the mushrooms to a cutting board and let cool slightly, then coarsely chop. Add enough water to the strained liquid to equal 4 1/2 cups; set aside the mushrooms and liquid for Step 4.

Cover edamame with water in a small saucepan and bring to a boil over high heat. Reduce heat to medium and simmer for 2 minutes; set aside in the cooking water.

Meanwhile, place rice and shallot in a shallow 3-quart baking dish that will fit and rotate properly in your microwave. Stir in oil until the rice is evenly coated. Spread the rice evenly in the dish and microwave, uncovered, on High until it looks opaque and is just beginning to color in one or two spots, 3 minutes.

Add lemon zest and juice, salt, pepper, the reserved chopped mushrooms and the mushroom water; stir together well. Microwave on High for 9 minutes. Stir well, then microwave until the rice is tender but still firm in the center and most of the liquid has been absorbed, 9 minutes more. Depending on the power of your microwave, this last cooking time will vary. After 9 minutes, cook in 3-minute intervals, stopping to stir and test rice for doneness. Drain the edamame and add to the risotto along with arugula and Parmesan; stir until the arugula is wilted. Serve immediately.