One-Pan Tuscan Chicken

Name: One-Pan Tuscan Chicken
Prep time: 15 min
Cook time: 35 min
Total time: 50 min
Cuisine: Italian
Ingredients: 1 small yellow onion; 3 cloves garlic; 1/2 cup drained oil-packed sun-dried tomatoes (2 1/2 ounces); 1 ounce Parmesan cheese (1/2 cup firmly packed freshly grated or 1/3 cup store-bought grated); 2 large boneless, skinless chicken breasts (1 1/2 to 2 pounds total); 1 1/2 teaspoons kosher salt, divided; 1/2 teaspoon freshly ground black pepper; 2 to 3 tablespoons olive oil, divided; 2 teaspoons dried Italian seasoning; 5 ounces baby spinach (about 5 packed cups); 1 1/4 cups heavy cream