Core apples. Cut each apple into 8 wedges; halve wedges crosswise.
Heat 2 tablespoons butter in a large skillet over medium heat. Add apples and 1 teaspoon each fresh thyme leaves and grated lemon zest; season with coarse salt and ground pepper. Cook, tossing occasionally, until apples are just tender when pierced with the tip of a paring knife, 3 to 5 minutes.