Vadouvan Naan with Salted Coconut Butter

To make the vadouvan naan:

1. Mix flour, vadouvan spice mixture, yeast, salt, baking powder, and sesame seeds in a bowl. 
2. Mix the milk, yogurt, egg, 2 tablespoons of grapeseed oil, and honey in the bowl of a stand mixer fitted with a dough hook attachment. 
3. Add the dry ingredients and mix on low speed for 5 minutes, or until a smooth and elastic dough is formed.
4. Place the dough into an oiled bowl with enough space to allow the dough to double in size, cover with plastic wrap, and set aside in a warm draft-free place to allow the dough to rise for about 2 hours, or until it is doubled in size. Gently press down the dough then cover it again with plastic wrap and allow it to rise until doubled in size, about 1 hour. 

To cook the naan and serve:

1. Heat a heavy cast-iron griddle over medium-low heat. 
2. Gently press down the dough again and form the dough into eight 4-ounce balls. 
3. Roll out each ball of dough into about a 7-inch disc using as little flour as possible to keep the dough from sticking to your work surface. 
4. When the griddle is very hot, brush it with some of the oil and place one rolled disc onto the heated griddle and cook until golden brown on the first side, about 2 minutes, then flip the naan and cook until golden brown spots form on the bottom, about 2 minutes. 
5. Serve the warm naan with the salted coconut butter on the side.
   

To make the salted coconut butter:

1. Combine all the ingredients in the bowl of an electric stand mixer fitted with a whisk attachment. Stir on low speed until all the coconut milk is incorporated in the butter. 
2. Increase the speed to high and whip until the butter is light and fluffy, about 3 minutes. 
3. Spoon the butter into small ramekins and keep at room temperature.

Vadouvan Spice Mix:

1. Working in 3 batches, pulse the onions in a food processor until they are coarsely chopped. Transfer the onions to a bowl after each batch is pulsed. Repeat with the shallots then the garlic.
2. Heat the oil in a deep 12-inch heavy nonstick skillet over high heat until it shimmers, then add the onions, shallots, and garlic and sauté until they are golden and browned in spots, 25 to 30 minutes.
3. Meanwhile, position the rack in the center of the oven and preheat the oven to 350°F. Line a heavy large rimmed baking sheet with parchment paper.
4. Grind the fenugreek seeds in a clean coffee grinder or with a mortar and pestle. Stir the ground fenugreek into the onion mixture along with remaining ingredients.
5. Transfer the onion mixture to the prepared baking sheet and spread the mixture as thinly and evenly as possible over the baking sheet. Bake, stirring occasionally with a skewer to separate the onions, until well-browned and barely moist, about 1 hour. Cool completely.