Wash and dry sweet potatoes. Prick each potato 4 to 6 times with a fork. Microwave on a plate until just tender, flipping halfway through, about 5 minutes.

Meanwhile preheat the oven to 425 degrees F (220 degrees C). Line a baking sheet with parchment paper. Cut sweet potatoes into 1-inch-thick slices. Place sliced sweet potatoes on the prepared sheet and gently smash each to about 1/2-inch-thick using a glass.

In a small skillet, melt butter over medium heat. Add garlic and sauté until fragrant, 30 to 60 seconds. Stir in Greek seasoning, salt, and pepper. Remove from heat.

Brush or spoon the garlic butter over each smashed potato. Drizzle with olive oil.

Bake in the preheated oven until edges are golden and slightly crisp, 20 to 25 minutes. Remove potatoes from the oven.

Sprinkle with Parmesan and thyme. Drizzle with balsamic glaze just before serving.