adapted from Bon Appetit
1 cup water
3/4 cup yellow cornmeal
3 garlic cloves, minced
1/2 teaspoon salt
1/2 cup freshly grated Parmesan cheese
2 4-ounce cans chopped green chilies, drained
1 cup drained canned corn, divided
2/3 cup chopped fresh cilantro, divided
2 cups grated Monterey Jack cheese
1/4 cup milk 1/4 cup sour cream
Preheat oven to 400°F. Butter 8 x 8 x 2-inch glass baking dish.
Mix first 5 ingredients (2 cups milk through salt) in a heavy medium saucepan. Bring to a simmer over medium heat, whisking constantly. Cook until polenta is tender and thickens, stirring often, about 12 minutes. Season with salt and pepper. Stir in Parmesan.
Pour half of polenta into prepared dish, spread evenly to the edges. sprinkle with one can of the chilies and half of corn. Top that with half of the cilantro followed by 1 cup of Jack cheese.
Combine the 1/4 cup milk and 1/4 cup of sour cream, whisk together to completely incorporate. Drizzle half of the sour cream mixture over the shredded cheese. Spoon remaining polenta over, again, spreading to the edges evenly. Cover with remaining chilies, corn, cilantro and cheese. Pour the last 1/4 cup sour cream mixture over. (Can be made 1 day ahead to this point. Chill.)
Bake until polenta puffs and cheese begins to brown, about 25 minutes if not chilled or 30 minutes if chilled. Cut into squares and serve.