In a large saucepan heat the chicken stock to a boil. Reduce heat and simmer until ready to use. In a large heavy pot heat 2 tablespoons butter and 2 tablespoons olive oil over moderate heat. Small children can help by taking paper off butter, cutting 2 tablespoons with butter knife, and dropping it into the pot. Small children should be highly supervised over each step that involves any type of gadget or working near a heat source. Add half of the onions to the pot and cook until clear, about 5 to 8 minutes. If you have older children, they can begin wiping off the shiitake caps with a damp cloth, removing the stems, cutting off the end, slicing the stems lengthwise and then slicing the caps.
Add the rice to the onions and stir to coat. Small children can do this well once they practice and learn a controlled stirring motion. "Slow and steady" can be repeated until they get the hang of it.
Add 1/3 cup white wine and stir until completely absorbed. Constant stirring will be required from here on out to make a good risotto. Have the children equipped with a long handled ladle and a deep oven mitt carefully dip the ladle into the broth and pour it into the rice. Stir continuously until the stock is absorbed. Repeat over and over using as much stock as necessary until the rice is cooked through but not mushy. The risotto should be creamy, slightly soupy but not watery.
Meanwhile, in a medium skillet heat 2 tablespoons butter and 1 tablespoon olive oil until melted. Add the other half of the chopped onion and stir to coat. Have the children cut the red pepper with table knives into strips and then crosswise into small even squares. Add the diced pepper to the onion and stir to combine. Add the tomatoes and stir to combine. Add the shiitakes and cook until any liquid evaporates. Add the fresh seafood and cook until just done.
Stir the sauteed seafood and vegetables into the pot of risotto. Grated Parmesan can be stirred into the risotto or served on top at the table. Cover until ready for service.