Sauce

• 2½ cups unsweetened plant-based milk
• 2 tsp lemon juice
• 1 tsp Dijon mustard
• ¾ cup whole wheat flour
• 3 Tbsp nutritional yeast flakes
• 1 tsp garlic powder
• 1 tsp onion powder
• ½ tsp ground turmeric
• ¾ tsp sea salt
• ½ tsp black pepper

Potatoes

• 2 pounds russet potatoes (about 6 medium), peeled and cut into ¼-inch-thick slices
• 2 onions, cut into ¼-inch-thick slices
• ½ cup chopped fresh parsley
• ¼ tsp smoked paprika