Lemony Mustard-Glazed Parsnips with Caramelized Onions

1. Parboil the Parsnips

Begin by bringing 3 quarts of water to a boil in a large pot. Add 1 tablespoon of kosher salt and the peeled parsnips. Cook the parsnips for 4-5 minutes, then drain and set them aside.

2. Marinate the Parsnips and Onions

In a large bowl or baking dish, combine the fresh lemon juice, 6 tablespoons of water, ¼ cup of peanut oil, 1 teaspoon of kosher salt, and a generous amount of freshly ground black pepper. Cut the parboiled parsnips into pieces and add them to the bowl along with the onion rings. Toss everything together until well coated, then cover and refrigerate for at least 2 hours, or preferably overnight, to let the flavors meld.

3. Caramelize the Onions

When you're ready to cook, heat 2 tablespoons of peanut oil in a sauté pan over medium heat. Add the marinated onions and cook them slowly, stirring occasionally, for 30-45 minutes until they are deeply caramelized. Add the mustard seeds, minced garlic, and minced habanero chile, and cook for an additional 3-4 minutes until the spices are fragrant.

4. Roast the Parsnips

While the onions are cooking, preheat your oven to 450°F. Line a baking sheet with parchment paper and spread the marinated parsnips in a single layer. Roast the parsnips for about 30 minutes, stirring every 10 minutes, until they are fork-tender and starting to brown.

5. Prepare the Sauce

To make the sauce, take ½ cup of the caramelized onion mixture and place it in a blender along with some of the reserved marinade and the Dijon mustard. Blend until creamy, then transfer to a pan and simmer for 3-5 minutes to thicken slightly.

6. Serve the Dish

To serve, spread a layer of the onion-mustard sauce on a plate. Arrange the roasted parsnips on top, then drizzle with more sauce. Garnish with the remaining caramelized onions, crushed peanuts, and fresh thyme leaves.