Preheat your oven to 450°F and prepare a baking sheet with parchment paper.

Trim the tops and a thin layer from the bottoms of the eggplants, then slice them into 1-inch-thick rounds. Arrange the slices on the prepared baking sheet.

In a small bowl, mix together the olive oil, minced garlic, cumin, salt, and red pepper flakes. Generously brush the mixture over the top side of each eggplant slice. Flip the slices and coat the other side as well.

Roast the eggplants in the oven for 20 minutes. Afterward, flip the slices over and continue roasting for an additional 10 to 20 minutes, until the eggplants are tender, browned, and slightly crisp on the edges. If desired, broil for 1 minute to add extra browning.