Cook the pasta to al dente according to package instructions, then drain, reserving some of the pasta water.
Heat a large skillet over medium heat and add the butter and olive oil. Once the butter has melted, add the onion and cook for 4-5 minutes until softened. Add the garlic and cook for another minute.
Add the tomato passata, dried basil, crumbled chicken bouillon cube, sugar, red chili flakes and salt and pepper to taste. Simmer for a few minutes, then add the cream, milk and the shredded mozzarella.
Add the cooked pasta, toss to combine and warm through for a few minutes. If sauce is too thick, add a splash of pasta water. Enjoy immediately!
