Preheat oven to 300 ºF.
Wash and quarter the tomatoes. Place on a baking sheet lined with parchment paper. Drizzle with 1 - 2 tbsp olive oil, just enough to make the tomatoes glisten. Bake for 1 hour in the oven.
Ten minutes before tomatoes are finished, fill a large pot with water and a sprinkle of salt. Bring to a rapid boil. Add the dry fettuccine to the water and cook until al dente.
While the pasta is boiling, add 2 tbsp olive oil, avocado, garlic, salt and lemon juice to a food processor. Pulse until the ingredients are smooth and creamy.
Strain the pasta, and combine with the sauce in a large bowl, until all the pasta has been covered.
Add the roasted tomatoes, sprinkle with Parmesan cheese and pine nuts. Add some salt and black pepper to taste.