Cut the tomatoes in half lengthwise and scoop out the seeds.
In a medium bowl, mix together the tuna, olive oil, garlic, goat cheese, parsley, salt and pepper.
Fill the tomato halves with the tuna mixture.
Spray a baking sheet with non-stick cooking spray and place the tomatoes on it. Bake in the preheated oven for 15 minutes, or until the tomatoes are tender.