Creamy Tomato Basil Tortellini Weeknight Italian Comfort

Ingredients

• 1 (9-12 ounce / 255-340g) package cheese tortellini (fresh or refrigerated)
• 1 tablespoon / 15 ml olive oil
• 1 small yellow onion, finely chopped (about 1 cup / 113g)
• 2 cloves garlic, minced
• 1 (28 ounce / 794g) can crushed tomatoes
• 1/2 cup / 120 ml heavy cream (double cream in the UK)
• 1/4 cup / 15g fresh basil leaves, chopped, plus more for garnish
• 1/4 teaspoon red pepper flakes (optional)
• 1/2 teaspoon salt, or to taste
• 1/4 teaspoon black pepper, or to taste
• 2 tablespoons / 30g grated Parmesan cheese (optional)