1. Preheat oven to 400°F.
2. Cut off the top 1/4 of each tomato and scoop out the seeds and juice, leaving only the thick outside flesh.
3. Combine parsley, thyme, green onion, breadcrumbs, salt, pepper, garlic, and sour cream in a medium sized bowl.
4. Season the inside of each tomato with additional salt and pepper. Stuff each tomato with about 1/3 cup of filling. Place the tomatoes on a sheet tray and bake for about 15 minutes.
5. Remove tomatoes from oven and top each tomato with 1 tablespoon of gruyere cheese and drizzle with 1 teaspoon of olive oil. Put back into the oven for one to two minutes or until the cheese has melted. Let cool for 5 minutes and serve.