Why You’ll Love This Recipe

• Intense, deep flavor from roasted vegetables.
• Made with simple, fresh, and wholesome ingredients.
• A sophisticated yet comforting meal perfect for any occasion.
• Innovative grilled cheese croutons add a fun, delicious crunch.
• Excellent for meal prep and freezes beautifully.

Equipment You’ll Need

• Large rimmed baking sheet
• Large Dutch oven or heavy-bottomed pot
• High-powered blender or an immersion blender
• Chef’s knife
• Cutting board
• Large non-stick skillet

Ingredients

• For the Roasted Tomato Soup:
• 3 lbs Roma tomatoes, halved lengthwise
• 1 large yellow onion, cut into 8 wedges
• 1 head of garlic, top sliced off to expose cloves
• 1/4 cup extra-virgin olive oil, divided
• 1 teaspoon dried oregano
• Salt and freshly ground black pepper to taste
• 1 tablespoon unsalted butter
• 4 cups vegetable broth
• 1/2 cup packed fresh basil leaves, plus more for garnish
• 1/2 cup heavy cream (optional, for a richer soup)
• 1 teaspoon granulated sugar (optional, to balance acidity)
• For the Grilled Cheese Croutons:
• 4 slices of sturdy bread, such as sourdough or brioche
• 2 tablespoons unsalted butter, softened
• 1 cup shredded sharp cheddar or Gruyère cheese

Instructions

1. Step 1: Roast the Vegetables. Preheat your oven to 400°F (200°C). On a large rimmed baking sheet, toss the halved tomatoes and onion wedges with 2 tablespoons of olive oil, dried oregano, salt, and pepper. Place the head of garlic, cut-side up, on the sheet and drizzle it with a bit of olive oil. Arrange everything in a single layer.
2. Step 2: Bake Until Caramelized. Roast for 40-45 minutes, or until the vegetables are soft, lightly browned, and caramelized at the edges. The tomatoes should be slightly collapsed and fragrant.
3. Step 3: Sauté and Simmer. While the vegetables are roasting, heat the remaining 2 tablespoons of olive oil and 1 tablespoon of butter in a large Dutch oven over medium heat. Once the roasted vegetables are done, carefully squeeze the soft, roasted garlic cloves out of their skins and into the pot. Sauté for 30 seconds until fragrant. Add the roasted tomatoes and onions to the pot, along with the vegetable broth. Stir everything together, scraping up any browned bits from the bottom of the pot.
4. Step 4: Simmer and Infuse. Bring the soup to a boil, then reduce the heat to low, cover, and let it simmer for at least 20 minutes to allow the flavors to meld together.
5. Step 5: Blend the Soup. Remove the soup from the heat. Stir in the fresh basil leaves. Using an immersion blender, blend the soup directly in the pot until it’s completely smooth and velvety. Alternatively, carefully transfer the soup in batches to a high-powered blender (be sure to vent the lid to allow steam to escape) and blend until smooth. Return the blended soup to the pot.
6. Step 6: Finish the Soup. Stir in the heavy cream and sugar, if using. Taste and adjust the seasoning with more salt and pepper as needed. Keep warm over low heat.
7. Step 7: Make the Grilled Cheese Croutons. While the soup simmers, prepare the croutons. Butter one side of each slice of bread. Place two slices, butter-side down, in a large non-stick skillet over medium heat. Sprinkle the shredded cheese evenly over the bread. Top with the remaining two slices of bread, butter-side up.
8. Step 8: Grill and Cut. Cook for 3-4 minutes per side, until the bread is golden brown and crispy and the cheese is fully melted. Transfer the grilled cheese sandwiches to a cutting board and let them cool for a minute before cutting them into 1-inch cubes.
9. Step 9: Serve. Ladle the hot soup into bowls. Top generously with the grilled cheese croutons and a garnish of fresh basil. Serve immediately and enjoy.

Expert Cooking Tips

• Use Ripe Tomatoes: The better your tomatoes, the better your soup. Use ripe, in-season Roma or plum tomatoes for the best flavor and texture.
• Don’t Crowd the Pan: When roasting, ensure the vegetables are in a single layer. Overcrowding will cause them to steam instead of roast, robbing you of that deep, caramelized flavor.
• Blend Safely: If using a countertop blender, never fill it more than halfway with hot liquid. Remove the center cap from the lid and cover the opening with a folded kitchen towel to allow steam to escape safely.
• Taste and Adjust: Acidity in tomatoes can vary. Don’t be afraid to add a pinch of sugar to balance the flavors if the soup tastes too acidic. Always taste and adjust salt and pepper at the very end.

Substitutions and Variations

For a vegan version, omit the heavy cream or substitute with full-fat coconut milk for richness. For the croutons, use vegan butter and vegan cheese. If fresh basil is unavailable, you can use 2 teaspoons of dried basil, adding it with the oregano during roasting. Different cheeses like provolone, Swiss, or Monterey Jack work beautifully for the croutons. Gluten-free bread can be used for the croutons as well.

Common Mistakes to Avoid

A common mistake is under-roasting the vegetables. You want deep color and caramelization for maximum flavor, so don’t pull them from the oven too early. Another pitfall is not blending the soup enough, resulting in a stringy or chunky texture instead of a smooth, velvety one. Finally, be sure to make the croutons just before serving; if made too far in advance, they can become soggy.

Serving Suggestions

This soup is a complete meal on its own, but for a more elaborate dinner, serve it as a starter. It pairs beautifully with a simple arugula salad with a lemon vinaigrette. For extra garnish, add a swirl of pesto, a dollop of crème fraîche, or a sprinkle of red pepper flakes for some heat.

Storage and Reheating Tips

Store leftover soup in an airtight container in the refrigerator for up to 4 days. The soup also freezes exceptionally well. Let it cool completely, then transfer to freezer-safe containers or bags and freeze for up to 3 months. Reheat gently on the stovetop. Store the grilled cheese croutons separately in an airtight container at room temperature for up to 2 days, though they are best enjoyed fresh.

Frequently Asked Questions

Can I use canned tomatoes instead of fresh?

While fresh, roasted tomatoes provide the signature flavor of this recipe, you can use a 28-ounce can of high-quality whole peeled tomatoes in a pinch. Drain them, toss with the onion and garlic as instructed, and roast until they begin to caramelize.

Is this soup gluten-free?

The soup itself is naturally gluten-free. To make the entire dish gluten-free, simply use your favorite gluten-free bread to make the grilled cheese croutons.

Why is my soup orange instead of red?

The color can vary depending on the ripeness of your tomatoes and whether you add heavy cream. Roasting deepens the color, and adding cream will lighten it to a creamy orange-red. This is perfectly normal and delicious!

Conclusion

By taking a little extra time to roast your ingredients, you transform a simple soup into an unforgettable culinary experience. This Roasted Tomato Basil Soup with Grilled Cheese Croutons is the ultimate expression of comfort food—it’s rustic yet elegant, deeply flavorful, and incredibly satisfying. It’s a recipe that proves that the best meals are often born from simple ingredients treated with care. We hope this becomes a new staple in your kitchen for cozy nights in.