Save There's something about the smell of roasting tomatoes that stops me mid-afternoon—that caramelized sweetness creeping through the kitchen that makes you pause whatever you're doing. Years ago, I discovered that roasted tomato soup wasn't just about tomatoes; it was about catching them at their peak, when summer heat had done all the work for you. Add grilled cheese cubes floating on top, and suddenly you've got something that feels like a warm hug on a plate.
I made this for my sister on a rainy Tuesday when she showed up stressed about work, and by the time she finished that bowl with the melted cheese cubes dripping into the warm soup, she'd already forgotten half of what was bothering her. That's when I knew this recipe wasn't just good—it was the kind of meal that mattered.
Ingredients
- Ripe tomatoes (1.5 lbs): Look for ones that smell fragrant and give slightly when you press them; under-ripe tomatoes won't develop that caramelized depth you're after.
- Medium onion: The onion softens into the soup, adding natural sweetness that balances the tomato acidity.
- Garlic cloves (4): Don't skip roasting them whole—they transform into something sweet and mellow rather than sharp.
- Olive oil (2 tbsp): Good olive oil matters here since it's doing real work in the roasting pan.
- Salt and black pepper: Season generously; roasted vegetables need encouragement to shine.
- Dried thyme or basil (1 tsp): Thyme gives an earthier note, basil something brighter—choose based on your mood.
- Vegetable broth (2 cups): Use a broth you actually like drinking; it becomes part of your soup's backbone.
- Tomato paste (1 tbsp): This concentrate deepens the tomato flavor without diluting the soup further.
- Sugar (optional, 1 tsp): Only add if your tomatoes turned out acidic; you're balancing, not sweetening.
- Heavy cream or whole milk (½ cup, optional): Cream makes it luxurious, milk keeps it lighter—both work beautifully.
- Sandwich bread (4 slices): Use sturdy bread that won't collapse; thin, flimsy bread becomes mush inside the grilled cheese.
- Sharp cheddar cheese (4 oz): Sharp cheddar has personality that mellows perfectly when melted; mild cheddar disappears into the background.
- Unsalted butter (2 tbsp): Softened butter spreads easily and browns evenly without burning.
Instructions
- Heat your oven and prep the vegetables:
- Set the oven to 400°F and while it warms, halve your tomatoes and quarter the onion. You want everything roughly the same size so it roasts evenly. Scatter everything on a baking sheet, drizzle generously with olive oil, and season it like you mean it—salt, pepper, and your choice of herbs.
- Roast until caramelized:
- Slide the sheet into the oven and let it go for 25 to 30 minutes. You're looking for the tomato edges to darken and curl slightly, and for the whole pan to smell like concentrated tomato candy. The caramelization is where the magic happens.
- Build your soup base:
- Scrape everything—and I mean everything, including all those flavorful pan juices—into a large pot. Add your broth, tomato paste, and a teaspoon of sugar if your tomatoes tasted sharp. Bring it to a gentle simmer and let it bubble quietly for about 10 minutes so everything gets to know each other.
- Blend until silky:
- Here's where an immersion blender is your friend—you can blend right in the pot without transferring anything hot. If you only have a regular blender, work in batches and let the soup cool slightly first. Blend until it's completely smooth, then stir in cream or milk if you're using it. Taste and adjust your seasoning one final time.
- Make the grilled cheese croutons:
- Butter one side of each bread slice lightly but thoroughly. Press two slices together with cheese in the middle, buttered sides facing out. Heat a skillet over medium heat—you want it hot enough that the bread sizzles when it hits the pan but not so hot it burns before the cheese melts.
- Cook until golden and melty:
- Place your sandwich in the skillet and listen for that satisfying sizzle. After about 2 to 3 minutes, check the bottom; when it's deep golden brown, flip it carefully and cook the other side the same way. The cheese should be completely melted and slightly oozing at the edges when you pull it out.
- Cut and serve:
- Let the grilled cheese cool for just a minute, then cut it into 1-inch cubes. Ladle soup into bowls and crown each one with a handful of warm croutons. They'll start softening immediately, which is exactly what you want.
Save My nephew asked for thirds last month, which never happens with soup. When I asked why, he said it was because the grilled cheese pieces were like finding little prizes at the bottom of the bowl. That's the feeling I want this recipe to give you—comfort that surprises you.
Why Roasting Changes Everything
The difference between this soup and any other tomato soup you've had comes down to roasting. When tomatoes roast at high heat, their water evaporates and their natural sugars caramelize, creating depth and complexity that simmering alone can never achieve. The onion and garlic soften into almost creamy sweetness, and together they build a soup that tastes like it simmered for hours but took less than an afternoon. I learned this the hard way after making watery tomato soup once too many times, and now I'm evangelical about prepping everything for the oven first.
The Grilled Cheese Crouton Trick
Grilled cheese croutons aren't a decoration; they're the soul of this dish. They add textural contrast, richness, and a little moment of indulgence in every spoonful. The key is making them sturdy enough to hold up in hot soup for a few minutes but not so thick they're bread-heavy. I've learned that cutting them into cubes right after they cool slightly means they'll soften into the soup gradually, almost melting into it by the time you reach the bottom of the bowl.
Customizing Your Version
This recipe is a foundation, not a rule book. Some people add a pinch of smoked paprika for depth, others swirl in a little balsamic vinegar for complexity. I've experimented with Gruyère and mozzarella in the croutons, and both are delicious in different ways—sharper cheeses taste more sophisticated, milder ones let the tomato shine. The beauty is that once you understand how roasting builds flavor and how grilled cheese adds richness, you can play around and make it your own.
- Try adding fresh basil at the very end of cooking for brightness that hot basil would lose.
- A handful of croutons, tortilla strips, or even crispy bacon bits works if grilled cheese croutons don't call to you.
- For dairy-free versions, plant-based cheese melts fine, though it sometimes breaks differently when heated—go a degree lower heat.
Save This soup has become my go-to when someone needs comfort, and it never fails. There's something about serving it that feels like saying 'I care enough to make you something real.'
Recipe FAQs
- → How do I make the tomato soup smooth?
Blend the roasted tomatoes and aromatics using an immersion or countertop blender until creamy and smooth. Adding cream or milk enhances the texture.
- → Can I prepare the grilled cheese croutons ahead?
Yes, grill the sandwiches, then let them cool before cutting into cubes. Reheat briefly if preferred to restore crispiness.
- → What herbs work best in this soup?
Dried thyme or basil complement the roasted flavors well, adding subtle herbal notes without overpowering.
- → Any tips for roasting tomatoes evenly?
Arrange tomatoes cut side up on a baking sheet and roast at 400°F until soft and caramelized, about 25-30 minutes.
- → How can I make this suitable for a vegan diet?
Use plant-based butter, dairy-free cheese, and cream alternatives to keep the creamy and crispy elements plant-friendly.