Smoky Lentil Soup with Grown-Up Grilled Cheese Sandwiches

Happy National Grilled Cheese Sandwich Day! It’s the perfect opportunity to indulge in everyone’s childhood favorite lunch treat, along with its perfect partner, a bowl of smoky lentil soup. But we bet your mother didn’t make grilled cheese sandwiches like these, which are filled with nutty Gruyère, sweet caramelized onions and peppery arugula.

 

Smoky Lentil Soup with Grown-Up Grilled Cheese Sandwiches

 

For the soup:

3 thick-cut bacon slices

2 Tbs. olive oil

1 small yellow onion, diced

1 carrot, peeled and cut into 1/4-inch (6-mm) dice

1 celery stalk, cut into 1/4-inch (6-mm) dice

1 tsp. minced garlic

1 Tbs. tomato paste

1 tsp. smoked paprika

1/4 cup (1 1/2 oz./45 g) canned diced tomatoes, drained

3/4 cup (6 oz./180 g) red lentils, preferably Red Chief, picked over and rinsed

4 cups (32 fl. oz./1 l) chicken broth

Kosher salt and freshly ground pepper

Sour cream for garnish

 

For the sandwiches:

2 Tbs. olive oil, plus more for brushing

1 large yellow onion, sliced 1/4 inch (6 mm) thick

Kosher salt and freshly ground pepper

8 slices sweet batard, cut on the diagonal 1/2 inch (12 mm) thick

4 tsp. Dijon mustard

10 oz. (310 g) Gruyère cheese, thinly sliced

A handful of arugula

 

Preheat a large sauté pan over medium-high heat. Add the bacon and cook, turning occasionally, until crisp, 5 to 6 minutes. Drain on paper towels. Coarsely chop the bacon and set aside.

 

In the same sauté pan over medium-high heat, warm the olive oil. Add the onion, carrot, celery, garlic, tomato paste and paprika. Cover and cook, stirring occasionally, until the vegetables just start to soften, about 25 minutes. Add the tomatoes, lentils and broth. Cover, adjust the heat to a simmer, and cook until the lentils are tender, 35 to 40 minutes.

 

While the lentils are cooking, caramelize the onions for the sandwiches. In a griddle pan over medium heat, warm the 2 Tbs. olive oil. Add the onion and cook, stirring occasionally, until caramelized, about 30 minutes. Season with salt and pepper and transfer to a bowl. Wipe out the pan with paper towels.

 

When the lentils are tender, using a blender, and working in batches, carefully puree about half of the soup until it is not quite smooth. Return the puree to the pot with the remaining soup, stir and season with salt and pepper. Cover and keep warm over low heat while you finish the sandwiches.

 

Brush one side of each bread slice with olive oil. Turn the slices over and spread each with 1/2 tsp.
mustard. Place half of the cheese on 4 of the bread slices. Top evenly with the caramelized onions and then the remaining cheese. Top each sandwich with one of the remaining bread slices, oiled side up.

 

Preheat the griddle pan over medium-high heat. Working in batches, place the sandwiches on the pan and cook, turning once, until the bread is golden brown and the cheese is melted, 2 to 3 minutes per side. Transfer the sandwiches to a cutting board, gently open them and arrange the arugula on top. Close the sandwiches and cut them in half.

 

Pour the soup into warmed bowls and garnish with sour cream and the bacon. Serve immediately with grilled cheese sandwiches. Serves 4.

 

Williams-Sonoma Test Kitchen