If making ahead to bake and serve at a later date: Line 13x9-inch (3-quart) glass baking dish with 2 layers of plastic wrap, leaving enough overhang to completely enclose the assembled lasagna. Cool pork mixture completely, covered, 30 to 45 minutes in refrigerator before assembling lasagna. Assemble lasagna in dish; cover with another layer of plastic wrap. Freeze unbaked lasagna about 8 hours or until completely frozen. Transfer to labeled 2-gallon resealable freezer plastic bag. Remove air; seal and freeze up to three months. Reserve green onion greens for another use. To bake: Spray 13x9-inch (3-quart) glass baking dish with cooking spray. Remove plastic wrap from lasagna; transfer to baking dish. Cover tightly with foil; thaw completely in refrigerator, 12 to 24 hours. Heat oven to 350°F. Bake, covered, 45 minutes. Uncover; bake 10 to 15 minutes longer or until cheese begins to brown and casserole is hot and bubbling on edges (165°F in center). Let stand 5 minutes before cutting. Top with basil.