Prepare pasta according to package directions but reduce cooking time by a few minutes; drain.
In a large skillet over medium high heat, heat oil and then add mushrooms; cover and cook, stirring for 5 minutes. Stir in tomatoes and artichokes. Cover and simmer another 3-5 minutes. Remove from heat.
In a large bowl combine remaining ingredients, except for the mozzarella.
Fill shells with mixture and divide among 8 individual baking dishes coated with Pam. Spoon sauce over each portion. Cover with foil and bake for 20-25 minutes.
Sprinkle with cheese and bake uncovered for 10 minutes or until bubbly.