Brush an 8-by-8-2 1/2-inch glass baking dish with oil. Bring the water and kosher salt to a boil in a heavy, medium saucepan over medium heat. Add the polenta using a whisk to incorporate. Reduce the heat. Let simmer for about 10 minutes, stirring frequently. Add the cream, using a whisk to incorporate. Cook until the consistency is soft and thick, about 10 minutes. Remove from the heat and add the Parmesan cheese, using a whisk to incorporate. Pour the polenta into the prepared baking dish and spread evenly into the dish using a large spatula or the back of a large spoon. Refrigerate until chilled. To make the salsa: Mix the sun-dried tomatoes, basil, balsamic vinegar, garlic and pepper together in a small bowl.
To Assemble: Preheat the oven to 300 degrees F. Trim the edges of the polenta and cut into 36 squares. Top each square with 1/2 teaspoon of the salsa. Place on a foil- or parchment paper-lined baking sheet. Bake until slightly warm, 8 to 10 minutes. Serve warm.
Do-Ahead Tips: The polenta and the salsa can be prepared up to two days in advance. The squares can be assembled up to one day in advance. Bake as directed.
Recipe from Cocktail Food by Mary Corpening Barber and Sara Corpening Whiteford Published by Chronicle Books