Scrub Jerusalem artichoke tubers and cut out eyes.
Cut tubers into 1-inch pieces.
Mix olive oil, thyme, garlic, and sea salt together in a large bowl; add Jerusalem artichoke pieces and toss to coat. Arrange coated pieces in one evenly-spaced layer on a baking sheet.
Roast in the preheated oven until Jerusalem artichokes are tender, 35 to 45 minutes.