Wild Rice and Celeriac Gratin

Ingredients

• ¼ cup minced shallot or onion
• 3 Tbsp butter or oil
• 2 Tbsp flour
• 1 ½ cups milk, scalded (can be nondairy milk)
• ½ tsp sea salt
• Freshly milled white pepper
• ½ tsp grated nutmeg
• 1 Tbsp butter
• 1 small celeriac, peeled and grated
• Juice of 1 lemon
• 1 clove garlic, minced
• 2 Tbsp chopped parsley, plus extra for garnish
• Sea salt and freshly milled pepper
• 3 cups wild rice, cooked
• ½ cup grated Gruyère
• ¼ cup freshly grated parmesan