Preheat oven to 425 degrees F. Line a large baking sheet with parchment paper.

Squeeze lemon juice into a large bowl and add in about 6 to 8 cups water. Set aside.

Wash sunchokes and Yukon gold potatoes to remove any dirt, leaving skins on. Cut potatoes and sunchokes into ½-inch to ¾-inch chunks and place in the lemon water. Let soak for 10 to 15 minutes before draining off the liquid.

Use a kitchen towel to pat dry the potatoes and sunchokes. Add them back to the bowl with 2 tablespoons olive oil, 1 teaspoon dried thyme, 1 teaspoon kosher salt and ½ teaspoon black pepper. Toss to evenly coat.

Spread sunchokes and potatoes onto the parchment-lined baking sheet. Place on the middle rack of the preheated oven and roast for 30 to 35 minutes, tossing halfway through. Note: Roasting time depends on how crowded the pan is, as you want them to be slightly caramelized but not burnt.

Transfer to a serving bowl or platter, sprinkle with flaky sea salt and serve.