Sausage and Gnocchi Marinara

Bahan-bahan (4 porsi)

• 2 tablespoons olive oil, divided
• 1 pound Italian chicken sausage, sliced into bite-sized pieces
• 1 small white onion, diced
• 4 cloves garlic, minced
• 2 tablespoons tomato paste
• 1/2 teaspoon crushed red pepper flakes
• 1 (28-ounce) can whole San Marzano tomatoes, not drained!
• 1 (1-pound) package potato gnocchi
• 2 handfuls fresh baby spinach
• 1/2 cup roughly-chopped fresh basil leaves
• fine sea salt and freshly-ground black pepper
• freshly-grated Parmesan