Caramelized Leek, Spinach, and Goat Cheese Tart

During the holiday season, I’m always looking for easy, foolproof recipes that can do it all: Feed me for dinner, wow last-minute guests, and help me get my fill of veggies, too.

This impressive dish does exactly that. Need a break from your usual weeknight pastas and casseroles? This vibrant tart will switch things up. Hosting vegetarian guests? Pop this guy in the oven. The filling is a deeply savory combination of caramelized leeks (cook ’em just like you would onions!), balsamic vinegar, and baby spinach for freshness, all piled onto a flaky puff pastry shell slathered with Dijon mustard and herbed goat cheese. Finish with Parm and devour it warm, then prepare to make it on repeat this season.

Ingredients:

• 1 (about 14-ounce) package or 1/2 (17.3-ounce) package frozen puff pastry, such as Dufour, thawed according to package directions
• 2 ounces garlic and herb goat cheese or Boursin
• 3 medium leeks (about 2 1/4 pounds total)
• 3/4 ounce Pecorino or Parmesan cheese, divided
• 1 large egg
• 1 teaspoon water, plus more as needed
• 2 tablespoons olive oil
• 1/2 teaspoon kosher salt, plus more as needed
• 2 teaspoons balsamic vinegar
• 5 ounces baby spinach (about 5 cups)
• Freshly ground black pepper
• 2 teaspoons Dijon mustard