1 | Heat oil in large skillet over medium-high heat. Add onion, garlic, jalapeño, and cumin, and sauté 5 minutes. Stir in beans, tomatoes,
1 cup corn, and lime juice; season with salt and pepper, if desired. Cook 5 minutes, or until heated through. Transfer mixture to covered container, and keep warm. Wipe out skillet.
2 | Meanwhile, crumble polenta into microwave-safe bowl, and mash with fork until nearly smooth. Add remaining 1/2 cup corn kernels. Microwave 1 minute to soften polenta. Stir, then add beaten egg, and fold into polenta mixture until smooth.
3 | Coat skillet with cooking spray, and heat over medium-high heat. Shape polenta into 8 1/3-cup cakes, gently flattening with palm. Cook corn cakes in two batches in skillet 5 minutes per side, or until golden brown. Serve corn cakes over black bean mixture.