At her award-winning Blue Heron restaurant in Montague, Massachusetts, chef Deborah Snow serves this delicious variation on plain polenta topped with everything from her ragout of wild mushrooms to her tomatoey shellfish stew to grilled rib-eye steaks or lamb chops.
Snap trimmed cobs into large pieces and place in a small stockpot with garlic and onion. Cover with 5 cups cold water.
Bring to a boil; then lower heat and simmer, partially covered, 30 minutes to 1 hour.
While broth is cooking, heat oil in a large skillet over high heat. Toss in corn kernels, stirring to separate.
Lower heat to medium and “roast” kernels, stirring occasionally, until slightly browned and caramelized, about 5 minutes. Remove from heat.
Strain broth and discard onions and garlic. Measure 3 cups broth into a heavy-bottomed saucepan; keep the remainder (about 1-½ cups) nearby. Add salt to broth in saucepan and bring to a steady boil.
Stirring continuously to prevent lumps, pour in cornmeal in a slow stream. When it thickens and starts to bubble vigorously, lower heat and cook about 20 minutes, stirring continuously. If it stiffens, stir in some reserved broth to maintain the consistency of mashed potatoes.
After about 20 minutes, stir in corn kernels and butter; cook 2 minutes, stirring. Remove pan from heat; stir in cheeses. Add heavy cream (if using).
Taste and adjust seasoning; add more broth as desired for a looser texture. Serve hot.