1. Bring a large pot of water to a boil over high heat. Stir in a heaping teaspoonful of salt, then add spaghetti. Stir well and cook until just al dente, about 11 minutes,stirring once or twice.
2. While pasta cooks, heat oil in a large skillet over medium heat. Add onion, garlic, and red pepper flakes. Cook and stir until onion begins to soften, about 5 minutes. Add anchovy paste and tomato paste. Stir until evenly blended.
3. Add tomatoes, olives, and capers. Stir well and bring to a simmer, about 10minutes, then reduce heat to medium-low.
4. Drain spaghetti and transfer to a large serving bowl or platter.
5. Use a fork to break up the tuna and add to the sauce; stir to distribute. Pour sauce over the spaghetti and toss until just coated. Sprinkle with parsley, if desired, and serve immediately.
Source: Hannaford fresh Magazine, March - April 2013