Cook tagliatelle pasta according to package instructions until al dente.

Drain pasta, rinse with cold water, drizzle with olive oil, and set aside.

Boil tomatoes until the skin peels off.

Peel and chop the tomatoes, reserving the juices.

Heat olive oil in a saucepan over medium heat.

Add chopped garlic and onions, stir until softened.

Add chopped tomatoes, basil leaves, salt, sugar, and black peppercorns.

Use a hand blender to coarsely puree the sauce.

Simmer the sauce for 20-30 minutes, covered slightly ajar, until thickened.

Season with salt and red chili flakes.

Add cooked pasta and toss to combine.

Serve garnished with Parmesan flakes and fresh basil.