Bring a large pot of salted water to a boil.

Add penne pasta and cook according to package directions.

Drain the pasta and set aside.

While the pasta is cooking, heat 1 1/2 tablespoons of reserved tuna oil in a large skillet over medium heat.

Add minced garlic and cook until fragrant, about 1 minute.

Stir in caponata, lemon juice, chopped parsley, and red pepper flakes.

Break tuna into chunks and gently stir into the caponata mixture.

Cook until heated through, about 2 minutes.

Toss the cooked pasta with the tuna and caponata sauce.

Serve immediately.