How to Make It
In a large skillet, heat 2 tablespoons of the olive oil. Add the shiitake and season with salt and pepper. Cover and cook over moderate heat, stirring occasionally, until tender and starting to brown, about 6 minutes; uncover and cook until browned, about 2 minutes. Transfer the mushrooms to a bowl.
Heat 1 tablespoon of the olive oil in the same skillet. Add the squid, season with salt and pepper and stir over high heat for 1 minute. Scrape the squid and any juices into another bowl; cover.
In a medium saucepan, bring the clam juice and water to a boil. Cover and keep hot over low heat. In another medium saucepan, heat the remaining 1 tablespoon of olive oil. Add the onion and garlic and cook over low heat, stirring occasionally, until softened, about 4 minutes. Add the rice and stir over moderate heat until coated with the oil. Add the wine and saffron and simmer until almost evaporated. Add enough of the hot clam broth to just cover the rice and cook, stirring, until the broth is almost absorbed. Repeat until the rice is al dente and bound in a creamy sauce, about 25 minutes. Keep the remaining 1/2 cup of broth hot.
Stir the shiitake and butter into the rice, then stir in the squid and its juices. Add the remaining clam broth and the lemon juice and zest and stir well. Remove from the heat and stir in the tomatoes, basil and sage. Season with salt and pepper. Spoon the risotto into shallow bowls and serve.