Heat the olive oil in a large, lidded pan over a medium heat. Shape the sausage meat into small, evenly sized meatballs and add them directly to the pan. Cook for 5–6 minutes, turning occasionally, until golden all over. Lift out with a slotted spoon and set aside.
Add the onion and fennel to the pan with a pinch of salt and pepper. Stir well and cook for 5–6 minutes, until softened and lightly translucent. Stir through the garlic, tomato purée and oregano and cook for a minute or two until fragrant. Pour in the white wine to deglaze the pan, scraping up any caramelised bits, and simmer for 2–3 minutes.
Return the meatballs to the pan, then add the chopped tomatoes and chicken stock. Season to taste, bring to the boil, then cover, reduce the heat and simmer gently for 30 minutes to allow the flavours to deepen.
Increase the heat slightly and bring the soup back to a gentle boil. Add the tortellini, spinach and double cream, stirring to combine, and cook for 1–2 minutes until the pasta is just tender and the spinach has wilted.
Taste and adjust the seasoning, then ladle into warm bowls and finish with a generous sprinkle of grated Parmesan.
