Cook the spaghetti in a large pot of salted boiling water according to package instructions.
While the pasta cooks, heat olive oil in a pan over medium heat.
Add minced garlic and sauté for 1 minute until fragrant.
Add halved cherry tomatoes and cook for 2-3 minutes until softened.
Drain the canned tuna and add it to the pan, breaking it apart with a fork.
Season with salt and pepper to taste.
Once the pasta is cooked, reserve 1/2 cup of pasta water, then drain the rest.
Add the cooked spaghetti to the pan with tuna and tomatoes.
Toss everything together, adding reserved pasta water if needed to loosen the sauce.
Stir in fresh basil and serve immediately with grated Parmesan on top.