Fit pie crust into a 9-inch quiche dish. Prick bottom and sides with a fork. Bake crust at 450 degrees for 12 minutes. Set aside. Melt butter in a small pan over medium heat, add onion and saute until tender. Add cream cheese and milk. Cook on low, whisking until cheese melts. In a separate bowl, whisk eggs, gently. Gradually add 1/4 of hot mixture into eggs to temper, then add egg mixture into the hot mixture, whisking constantly. Add in ham and remaining ingredients. Pour into
prepared crust. Bake at 350 degrees for
35 minutes.