Heat water in a cooking pot and cook pasta according to packagig instructions or until al dente. Set aside.
Heat oil (oil from tuna can) in a cooking pan over medium heat. Cook shrimps until pinkish in color and cooked through then set aside.
Using same pan (add more oil if needed), saute onions until translucent then add garlic and cook until fragrant.
Tip-in the halved cherry tomatoes and cook for 2-3 minutes or until soft and a bit wilted.
Add tuna chunks and stir. Cook for 3 minutes.
Pour-in the red pesto sauce and mix. Let simmer for 2-3 minutes.
Taste and season with salt and pepper.
To serve, place some pasta on a plate and pour red pesto sauce on top. Sprinkle some cheese and enjoy! Bon Appetit!