Sweet Corn Bread Pudding

• 1/2 onion, diced fine
• 1 ounce unsalted butter
• 1/2 teaspoon thyme
• 1/2 teaspoon rosemary
• 1 (15-ounce) can creamed style sweet corn
• 1 cup heavy cream
• 2 eggs
• 1 teaspoon baking powder
• 1/2 cup yellow cornmeal, whole grain, stone ground
• 1/2 cup shredded Parmesan
• 1 teaspoon kosher salt
• Ground black pepper
• 2 cups cubed French bread