Preheat oven to 350°F (180°C).

Trim leeks removing the dark green leaves and peeling off the tough outer layer.

Cut leeks lengthwise, leaving each half with root attached. Clean between the layers thouroughly under cold running water to remove sand and grit. Once clean, cut roots off.

Heat a medium oven-proof sauté pan over medium heat. Add olive oil.

Once oil is hot, add the garlic and the leeks, cut side down, in a SINGLE LAYER. You may have to do this in batches based on the size of your pan and the size of the leeks. Cook for 3-4 minutes until leeks have lightly browned.

Flip leeks and cook for another 3 minutes to lightly brown.

Once all of the leeks are browned on both sides, add wine, stock, thyme, salt, and pepper. Bring to a simmer, cover, and cook in the oven for 35 minutes or until leeks are tender.

Once tender, top with parmesan cheese and cook for another 3-5 minutes or until cheese has melted. Serve immediately.