Step 1

Preheat oven to 400° F.

Step 2

Cook bacon until crisp and crumble. Melt butter and lightly brush over bottom and sides of a well-seasoned cast-iron or non-stick 10-inch skillet.

Step 3

With a sharp knife peel celery root and, using a mandoline or other manual slicer, cut crosswise into 1/16-inch-thick slices. Arrange 1 slice in center of skillet and arrange one layer of slices around center slice in a concentric circle, overlapping them slightly. Lightly brush layer with some of melted butter (being careful not to move slices) and sprinkle with one third bacon, 1 1/2 tablespoons Parmesan, 3/4 teaspoon thyme, 1 teaspoon olives, and salt and pepper to taste. Repeat procedure twice but reverse direction of slices each time so that layers are even. Add one more layer of celery root. Brush top with any remaining butter and sprinkle with remaining 1 1/2 tablespoons Parmesan and remaining thyme. Cover top of skillet tightly with foil and bake celery root in middle of oven 20 minutes. Remove foil and bake 20 to 25 minutes more, or until celery root is tender and top and edges are golden brown.

Step 4

Transfer celery root Anna with 2 large spatulas to a cutting board and cut into wedges.