Parsnip Gratin Gelson's

Ingredients

• Butter, for greasing pan
• 2 ½ lb parsnips, cut crosswise into ⅛-inch thick slices
• 1 medium yellow onion, thinly sliced
• 8 oz Gruyère cheese, grated, divided
• 1 Tbsp Gelson’s organic thyme leaves, divided, plus more for garnish
• 2 ½ cups heavy whipping cream
• 1 ¼ tsp kosher salt
• ¼ tsp ground nutmeg, plus more for the top
• ¼ tsp white pepper
• 1 Tbsp all-purpose flour
• 3 large cloves garlic, minced