Heat oven to 350ºF.
Heat the olive oil in a large, oven-safe saucepan set over medium heat. Add the red onion and 1/2 teaspoon of the salt and sweat until the onions begin to turn translucent, 4 to 5 minutes. Reduce the heat to low, add the garlic, and saute for 1 to 2 minutes, making sure the garlic does not burn.
Turn the heat up to high, add the chicken broth, and bring to a boil. Gradually add the cornmeal, whisking constantly. Once you have added all of the cornmeal, cover the pot and place it in the oven. Cook for 35 to 40 minutes, stirring every 10 minutes to prevent lumps.
Once the mixture is creamy, remove it from the oven and add the butter, the remaining 1 teaspoon salt, and the pepper. Once they are incorporated, gradually add the Parmesan.
Serve as is, or pour the polenta into a 9-by-13-inch pan lined with parchment paper. Place in the refrigerator to cool completely.
Once set, turn the polenta out onto a cutting board and cut into squares, rounds, or triangles. Brush each side with olive oil and saute in a nonstick skillet over medium heat until golden brown on both sides.