To prepare pork, heat a large skillet over medium heat.
Add oil to pan; swirl to coat.
Add onion and garlic; saut 3 minutes.
Add greens and next 3 ingredients (through raisins); cover and cook 4 minutes or until greens wilt, stirring occasionally. Uncover, and cook 3 minutes or until liquid evaporates.
Place greens mixture in a food processor; pulse 3 times or until chopped.
Transfer mixture to a bowl.
Add breadcrumbs, rosemary, and salt, tossing to combine.
Cut horizontally through center of pork, cutting to, but not through, other side using a sharp knife; open flat as you would a book.
Place pork between 2 sheets of plastic wrap; pound to an even thickness using a meat mallet or small heavy skillet.
Layer pancetta over pork.
Spread dandelion stuffing over pork, leaving a 1/2-inch margin around outside edges.
Roll up pork, jelly-roll fashion, starting with short side. Secure at 2-inch intervals with twine.
Place pork in a shallow pan coated with cooking spray.
Bake at 450 for 15 minutes. Reduce oven temperature to 325; bake 30 minutes or until a thermometer inserted in center registers 14
Transfer pork to a platter, reserving drippings in pan. Cover pork with foil, and let stand 15 minutes.
To prepare sauce, stir broth, 1/4 cup muscadine wine, and white wine into pan drippings, scraping pan to loosen browned bits.
Pour wine mixture into a small saucepan.
Combine cornstarch and 1 tablespoon water in a small bowl.
Add cornstarch mixture to broth mixture; bring to a boil. Cook 1 minute, stirring constantly.