Prepare Chicken Meatballs:
In a mixing bowl mix together ground chicken, garlic, parsley, cheese, beaten egg, salt and pepper.
Loosely shape ground chicken mixture into meatballs no bigger than the inside palm of your hand. Should yield about 12 (1 1/2-inch in diameter) meatballs.
Heat olive oil in large nonstick frying skillet on stovetop, over medium-high heat.
Sear all sides of meatballs in hot oil until golden brown and a little firm to the touch.
Remove skillet from stove. Scrape bottom of skillet with a wooden spoon and pour remaining oil from skillet into a large nonstick pot (at least 6 quarts in size). Add 1/4 cup olive oil and place pot on stove top. Heat oil over medium heat. Saute rosemary for about 5 minutes. Remove rosemary from oil and discard. Add garlic and saute about 3 minutes, until aromatic and golden brown. Add red onion, sweet onion, shallot, and saute for about 5 minutes, until tender. Scoop out tomato paste from can, and add to onion, garlic and oil mixture. Saute paste for about 5 minutes, blending with onions and garlic using wooden spoon. Stir in plum tomatoes, chicken broth, parsley, basil, salt, pepper, and oregano. Add chicken meatballs and bring gravy to a low boil. Lower heat to very low. Cover pot, and cook gravy for 45 minutes, stirring at least every 15 minutes so gravy does not burn the bottom of the pan.
Uncover pot and add white wine, sage, nutmeg, and 1 tablespoon olive oil. Stir and simmer on low heat, uncovered for another 35 minutes, stirring at least every 15 minutes. Gravy should thicken and become a deep red color.
Note: If preparing ahead of time, cook gravy with meatballs for 10 more minutes, remove from heat and let cool completely before refrigerating or freezing.
Prepare multigrain spaghetti according to package directions.
To serve family style, spoon gravy on large serving platter. Top with cooked spaghetti dotted with chicken meatballs. Cover with gravy. Sprinkle with grated cheese and chopped parsley. Serve with extra gravy on the side, crusty Italian whole-wheat bread, and a salad with Italian dressing.