Ratatouille Pot Pie with Cornmeal Biscuits

FOR THE CORNMEAL BISCUITS
1 cup all-purpose flour
1/2 cup fine cornmeal
2 teaspoons sugar
1 1/2 teaspoons baking powder
1/4 teaspoon baking soda
1/4 teaspoon kosher salt
6 tablespoons cold, unsalted butter, cut into 1/2-inch cubes
3/4 cup sour cream or plain whole milk yogurt
Milk

FOR THE RATATOUILLE
1 large eggplant 1 1/2 pounds cut into 1-inch chunks
3 small zucchini 3/4 pound, cut into 1-inch chunks
7 tablespoons extra virgin olive oil
1 teaspoon kosher salt
3/4 teaspoon freshly ground black pepper
3/4 pound Italian sausage, casings removed
1 large onion, cut into 1-inch chunks
1 red pepper, cored and cut into 1-inch chunks
3 large garlic cloves, finely chopped
1 1/2 pounds plum tomatoes
4 sprigs fresh thyme
1/4 cup chopped fresh parsley or basil 


For the biscuits: In a bowl, whisk together the flour, cornmeal, sugar, baking powder, baking soda and salt. Using a pastry cutter or fork, cut in the butter until mixture resembles coarse crumbs. Fold in the sour cream. Gently knead mixture until it comes together in a ball, adding a drop or two of milk if necessary. Cover with plastic wrap and refrigerate until ready to use. Preheat oven to 450 degrees.

For the ratatouille: In a bowl, toss eggplant and zucchini with 5 tablespoons oil; season with ¾ teaspoon salt and ¾ teaspoon pepper. Spread vegetables in a single layer on one or two large baking sheets (do not crowd vegetables). Transfer to oven and roast, tossing occasionally, until golden, about 20 minutes.

Meanwhile, in a large, deep, preferably oven-proof sauté pan, heat 1 tablespoon oil. Crumble sausage into pan and cook over medium heat, stirring occasionally, until golden, about 7 minutes. Use a slotted spoon to transfer sausage to a paper towel-lined plate.

Return pan to medium heat and add remaining 1 tablespoon oil. Stir in the onion, pepper, garlic and remaining ¼ teaspoon salt. Cook until softened, 5 to 7 minutes. Stir in the tomatoes and thyme sprigs; simmer gently until tomatoes are cooked and mixture is stew-like, about 10 minutes. Stir in the sausage, roasted vegetables and parsley. If you are not using an oven-safe pan, transfer mixture to a 2-quart gratin dish or baking pan.

Divide biscuit dough into six equal balls. Use your palm to flatten each ball into a ½ -inch-thick disk. Arrange on top of ratatouille mixture. Brush biscuits lightly with milk.

Transfer skillet or pan to oven and cook until biscuits are golden, 25 to 30 minutes. Let cool 10 minutes before serving.