In a heavy bottom pan, heat olive oil and butter together.
Add garlic and fry for couple of minutes.
Now, add onions and fry until soft and pink.
Add chopped tomatoes, dill leaves, tomato ketchup, Italian seasonings and mix. Cook on high for 2 minutes. Cover and cook until the tomatoes are cooked well.
Using a hand blender or a normal blender, carefully blend the cooked tomatoes mixture until smooth.
Now, add vegetable stock and bring it to a boil. Season with salt, pepper and chilli flakes. Once the soup comes to boil, add penne regaté and cook Al denté.
Tomato pasta soup is ready to be served. Dish out and garnish with grated mozzarella cheese and serve immediately.