Shrimp Scampi with Creamy Polenta

In a medium pot, bring 5 cups water to a boil and season with salt. Slowly add cornmeal, whisking constantly to prevent lumps. Reduce heat to low and simmer, stirring occasionally, 20 minutes. Add Parmesan and 1 tablespoon butter. (Polenta should be thick but have a soft consistency. Keep warm until ready to serve.) In a medium bowl, season shrimp with salt and pepper; set aside. In a large skillet, heat olive oil over medium-low heat. Add garlic, onion, and red pepper flakes and cook until onions are tender, 5 minutes. Add shrimp and cook, stirring occasionally, until just pink; transfer to a plate. Increase heat to medium-high; add wine and lemon juice and simmer until sauce has reduced, 3 to 4 minutes. Turn off heat and add butter, shrimp, and chives. Serve shrimp over polenta with sauce and chives.