Description

Roasted tomatoes, sweet onion, and mellow garlic set the tone for this comforting Roasted Tomato Basil Soup with Parmesan Sourdough Croutons. Fresh basil and a splash of cream round out the rich tomato flavor, while golden, cheese-crusted sourdough adds a crisp finish. It’s a cozy bowl with a little grilled-cheese spirit—just enough richness to hit the right note without weighing down the whole performance.

Ingredients

Units Scale

Soup

3 pounds Roma tomatoes (10 to 12 medium), halved lengthwise
12 1/2 cups sweet onion, cut into 1-inch wedges
1 medium head garlic (about 10 to 12 cloves)
2 tablespoons olive oil, divided
1 teaspoon kosher salt, divided
3/4 teaspoon freshly ground black pepper, divided
2 tablespoons unsalted butter
2 tablespoons tomato paste
1/4 teaspoon crushed red pepper flakes (optional)
1/4 cup dry white wine, such as Sauvignon Blanc or Pinot Grigio
3 cups low-sodium chicken broth, plus up to 1 cup more as needed
1 Parmesan rind (optional but recommended)
2 1/2 packed cups fresh basil leaves
1/3 cup heavy cream
2 tablespoons freshly grated Parmesan cheese
1 teaspoon granulated sugar, if needed

Parmesan Sourdough Croutons

2 cups sourdough bread, cut into 3/4-inch cubes
2 teaspoons olive oil
1/4 teaspoon garlic powder
1/4 cup finely grated Parmesan

For Garnish

Fresh basil ribbons
Freshly cracked black pepper
4 teaspoons basil pesto (1 teaspoon per serving)
1-2 teaspoons warm water, as needed to thin the pesto

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Instructions

Preheat the oven to 425°F.
Arrange the tomatoes cut-side up on a large rimmed baking sheet (18 x 13 inches), with the onion wedges spread around them in a single layer.
Slice about ¼ inch off the top of the garlic head. Drizzle the exposed cloves with ½ teaspoon of the olive oil, wrap loosely in foil, and place on the sheet pan.
Drizzle the tomatoes and onion with 1½ tablespoons of the olive oil and season with ½ teaspoon kosher salt and ½ teaspoon black pepper.
Roast for 40–45 minutes, or until the tomatoes have caramelized around the edges and the onion is tender.
Allow the garlic to cool just enough to handle, then squeeze the roasted cloves from the skins. Reduce the oven temperature to 400°F.
Heat the butter and remaining 1 teaspoon olive oil in a large Dutch oven over medium heat. Stir in the tomato paste and cook for 2 minutes, stirring frequently, until it darkens slightly. Add the crushed red pepper flakes, if using.
Pour in the white wine, scraping up any browned bits from the bottom of the pot, and simmer for 2 minutes until slightly reduced.
Add the roasted tomatoes, onion, roasted garlic, any juices from the sheet pan, 3 cups chicken broth, and Parmesan rind. Bring to a gentle simmer and cook for 15 minutes.
Meanwhile, toss the sourdough cubes with 2 teaspoons olive oil and the garlic powder. Spread on a parchment-lined baking sheet and bake at 400°F for 8–10 minutes, tossing halfway through, until lightly golden and crisp.
Gather the croutons close together in a single layer and sprinkle evenly with the Parmesan. Bake for another 2–3 minutes, until the cheese is melted and beginning to turn golden. Set aside to cool slightly, then separate into individual croutons.
Remove the Parmesan rind from the soup. Stir in the basil and cook for 1 minute, just until wilted.
Blend the soup until completely smooth using an immersion blender, or carefully blend in batches in a countertop blender, following its instructions for hot liquids.
Return the soup to low heat and stir in the heavy cream and grated Parmesan. If the soup is thicker than you like, gradually add some of the reserved broth until it reaches your preferred consistency.
Taste and season with the remaining salt and pepper as needed. If the tomatoes are especially acidic, stir in the sugar.
Heat gently for 2–3 minutes without boiling.
Thin the pesto with warm water as needed until spoonable. Ladle the soup into bowls and top with the Parmesan sourdough croutons. Spoon 1 teaspoon of pesto over each serving, finish with basil ribbons and freshly cracked black pepper, and serve immediately. Add the croutons just before serving so they stay crunchy.

Notes

Roasting tomatoes, onion, and garlic develops natural sweetness and rich depth. Blending the roasted vegetables gives the soup body, while a modest amount of butter and cream adds richness.

Start with 3 cups of broth and add more only after blending and adding the cream. The tomatoes’ moisture content will vary, so you may not need the full additional cup.

Adding the basil just before blending preserves its fresh flavor and aroma.

For an extra silky texture, pass the blended soup through a fine-mesh sieve before adding the cream and Parmesan.

Finely shred the Parmesan so it melts evenly over the croutons. Let them cool slightly before separating and add them to individual bowls just before serving to keep them crisp.

The soup will keep in an airtight container in the refrigerator for up to 4 days. Store the croutons separately. Reheat the soup gently over medium-low heat without boiling.

Prep Time: 15 minutes
Cook Time: 1 hour, 10 minutes
Category: Soup
Method: Roasting, Stove Top
Cuisine: American