1. Place pancetta in a large skillet over medium heat; cook 6 minutes or until pancetta begins to crisp, stirring occasionally. Add garlic; cook 30 seconds, stirring constantly. Add stock; bring to a boil. Reduce heat; simmer 4 minutes. Add the cream cheese and mascarpone, stirring with a whisk until smooth. Strain sauce through a fine sieve over a large bowl. Discard solids.
2. Cook pasta according to package directions; omitting salt and fat. Add asparagus and peas during last 2 minutes of cooking; cook 2 minutes. Drain. Add the pasta mixture, salt, and black pepper to sauce in bowl; toss well to combine. Sprinkle with parsley and chives.