Preheat oven to 375. Coarsely chop chicken and dice bell pepper. Place chicken and bell pepper in bowl. Chop parsley, zest lemon (1 tsp). Cut lemon into thin slices, then half slices, to be used for garnish.
Add parsley, lemon zest, garlic, mozzarella cheese, mayonnaise and Italian seasoning to chicken mixture; mix well. Grate Parmesan cheese, reserving 2 tbsp. Add remaining cheese to chicken mixture; mix well.
Unroll crescent dough; separate into 16 triangles. Arrange triangles, slightly overlapping, in a circle on large cooking stone (or pizza pan) with wide ends (in the center) approximately 4 inches from edge of stone (points may extend off the edge of the baking stone). Roll wide ends of dough toward center to create a 5 inch opening.
Spoon chicken mixture evenly over dough in a continuous circle. Bring points of triangles up over filling and tuck under dough at center to form a ring (filling will show). Sprinkle remaining Parmesan cheese over ring. Bake 28-30 minutes, or until golden brown. Remove from oven; garnish with lemon slices and remaining parsley.