Bring a large pot of water to a boil for pasta. Salt water and cook pasta to al dente.
Meanwhile, poach chicken. Place chicken in small pan and add water to top of meat but do not cover completely. Add bay leaf and bring to a boil, reduce heat and gently simmer to cook through 10-12 minutes. Shred meat into small pieces with forks or dice into small pieces.
While chicken cooks heat EVOO in large, deep saut pan over medium heat. Melt butter into oil and add onions and garlic, season with salt and pepper and cook 8-10 minutes, stirring occasionally. Sprinkle flour over cooked onions and garlic and stir 1 minute then whisk in white wine. Add stock and stir 1 minute then stir in cream and season with nutmeg. Thicken sauce a couple of minutes over low heat then stir in spinach and artichokes and heat through, melt Asiago or provolone cheese into sauce and turn off heat.
Drain pasta and toss with sauce and chicken to combine, adjust salt and pepper to your taste. Garnish with freshly grated Parmigiano-Reggiano cheese.