To make the basic risotto for the arancini, in a saucepan bring stock to a simmer. Cover and set aside to keep hot. In a heavy Dutch oven or large saucepan, melt 3 tablespoons of the butter over medium-high heat. Add the chopped onion and saute until transparent, about 4 minutes. Add rice and cook, stirring constantly, until rice is opaque and fragrant, about 1 minute. Add the white wine and cook, stirring, until absorbed. While continually stirring, begin adding the stock in 1/2 cup increments, allowing the liquid to become completely absorbed between additions. Cook until the rice is just tender and the risotto is creamy, about 20 minutes. Add the grated Parmigiano-Reggiano, heavy cream, herbs and salt and pepper and stir to combine well. Transfer to a mixing bowl or baking dish and allow to cool completely. Refrigerate until thoroughly chilled. When ready to "raid the refrigerator" and make the arancini, remove the chilled risotto from the refrigerator and stir in 1 of the eggs. Using a small scoop or large spoon, divide the risotto into approximately 3 tablespoon portions. Using your hands, form the portions into rough ball shapes.
Press a hole into the center of each risotto ball and stuff the center with some of the cheese and the Crabmeat. Press the opening closed and roll the ball between your hands until it is smooth. Set aside while you prepare the other arancini. In a large saucepan, heat 2 inches of oil until a deep-fry thermometer reads 360 degrees F. Place the flour, remaining 2 eggs and bread crumbs in 3 separate bowls. Using a fork, lightly beat the eggs. One by one, lightly dredge each risotto ball in the flour, then the beaten egg mixture, then the bread crumbs, so that each ball is completely coated.
Transfer to a plate or baking sheet until you are ready to fry the arancini. Fry the balls in batches, a few at a time, turning once during cooking so that they are evenly browned, about 2 minutes. Transfer to paper-lined plates to drain briefly, then serve immediately. Serve with Parmesan cheese and some creamy marinara sauce.