Preheat the oven to 425 degrees.
Use a sharp paring knife to remove the core from each tomato, then slice each on in half verti-cally. Place tomatoes cut-side-up in a casserole dish, then season generously with salt, pepper, and half of the fresh thyme leaves.
Divide the Finlandia Keisarinna cheese between the tomatoes, then sprinkle with panko bread-crumbs. Season with a little more salt, pepper, and the remaining thyme leaves, then drizzle with extra virgin olive oil.
Place on the top rack of the oven and bake for about 10-15 minutes, or until the cheese is melt-ed and the tops are golden. Serve hot.
If the tops haven't browned after 15 minutes, broil for 10-30 seconds, keeping a close eye on them until golden.