Preheat the smoker to 375°F.

In a large bowl, combine the sliced potatoes, onion, and minced garlic.

In a separate bowl, whisk together the heavy cream, chicken or vegetable broth, Dijon mustard, thyme leaves, salt, pepper, and smoked paprika.

Pour the cream mixture over the potato mixture and toss gently to coat the potatoes evenly.

Grease a large, disposable aluminum foil pan (about 9x13 inches) with butter or cooking spray. Layer half of the potato mixture in the pan, followed by 1 cup of the shredded cheddar cheese. Repeat with the remaining potato mixture and top with the remaining 1 cup of cheddar cheese, grated Parmesan, and the butter pieces.

Cover the pan tightly with aluminum foil and place it in the smoker. Smoke for 1 hour.

After 1 hour, remove the foil and continue smoking for an additional 30 minutes, or until the potatoes are tender and the cheese is golden brown and bubbly.

Remove the pan from the smoker and let the potatoes rest for 10-15 minutes before serving.