Vadouvan Naan with Salted Coconut Butter

Ingredients

• 3 1/2 cups all purpose flour
• 3 tablespoons Vadouvan (see recipe)
• 1 tablespoon instant yeast
• 2 teaspoons kosher salt
• 1 teaspoon baking powder
• 2 teaspoons black sesame seeds
• ½ cup whole milk
• ½ cup whole milk yogurt
• 1 jumbo egg
• 2 tablespoons grapeseed oil plus more for brushing the griddle
• 2 tablespoons honey
• ½ pound (2 sticks) unsalted butter, room temperature
• ½ cup stirred unsweetened coconut milk
• 2 teaspoons fleur de sel
• 2 pounds onions, peeled and cut into 1-inch pieces
• 2 pounds shallots, peeled and halved
• 12 garlic cloves, peeled
• ¼ cup grapeseed oil