Stuffed Zucchini

Bahan-bahan (4 porsi)

• 4 whole zucchini ((about 5 to 6 inches long))
• 2 tablespoons extra-virgin olive oil (divided)
• 1/2 pound ground Italian turkey sausage (casings removed)
• 1/2 cup finely chopped red onion
• 1 large red bell pepper (diced)
• 1/2 teaspoon kosher salt
• 1/4 teaspoon ground black pepper
• 1/8 teaspoon red pepper flakes
• 1 teaspoon minced garlic
• 2 tablespoons tomato paste
• 1/4 cup packed fresh basil leaves
• 2 slices whole wheat sandwich bread
• 1/2 cup freshly grated Parmesan (plus additional for serving)