Cook pasta 2 minutes less than recommended in package directions. Do not fully cook.
Drain and rinse pasta in cold water. Set aside.
Melt butter in a medium saucepan. Add onions and cook on medium high until browned and soft. They need to brown for flavor, but be careful not to burn them.
When almost all liquid released from the onions has evaporated, deglaze with white wine. Add herbs and salt to the pan. Cook on medium high until only 2 tbsp liquid are left in the pan.
Sprinkle flour over the onions and stir in. Add chicken stock to the pan and cook on medium high until only 2 tbsp liquid are left in the pan.
Add milk and cream to the pan and continue heating until they are hot. Do not walk away or allow to come to a boil.
Remove from heat and stir in 3/4 of the cheese until just melted.
Preheat oven to 350F.
Grease a 2 quart casserole pan with butter. Gently fold sauce into pasta and spread evenly in casserole. Sprinkle with remaining cheese and top with bread crumbs.
Bake 25-35 minutes or until bubbly and cheese is starting to brown. Allow to cool for at least 10 minutes before serving.