Summer may be the best season for tomatoes, but these cold winter days are the perfect time for tomato soup. Our Roasted Heirloom Tomato Soup can be frozen up to six months, so plan ahead and put your summer surplus or farmer’s market haul to work. During winter, it’s worth the splurge to pick up some heirloom tomatoes if you can find them.
What’s with the heirloom tomatoes? In a word, flavor. Each variety has a different flavor profile, from tangy citrus to sweet and smoky. For this recipe, we’re using a combination of pink, red, and black (or purple) to achieve a full classic tomato flavor that is sweet, rich, and smoky. To enhance this, we’re oven toasting the tomatoes, garlic, and bell pepper before putting everything together in the Instant Pot.Print
A rich and smoky tomato basil soup featuring roasted heirloom tomatoes and red bell pepper.
- 4 1/2 pounds ripe heirloom tomatoes (any variety or combination)
- 8 large cloves garlic, peeled
- 2 medium yellow onions, roughly chopped (about 2 cups)
- 1 large red bell pepper
- 1 14-ounce can unsalted broth (vegetable for vegan option, chicken for non-vegan option)
- 1 6-ounce can tomato paste (no sugar or seasoning added)
- 1 cup fresh whole basil leaves, firmly packed (discard stems)
- 1/2 cup water
- 2 tbsp plus 1 tsp extra-virgin olive oil
- 2 tsp Lakanto Classic Sweetener
- 2 tsp salt, divided
- 2 tbsp ghee
- 1/2 tsp ground black pepper
- 1/4 tsp dried rosemary
- 1/4 tsp dried thyme
- 1/8 tsp red pepper flakes (use 1/4 tsp if you like a little heat)
- Optional: Grain-free croutons (our paleo-compliant, grain-free English muffins are great for this), fresh sliced basil, shredded parmesan cheese (if not paleo or vegan)
Roasting the Vegetables
- Place oven racks in top two positions and preheat oven to 400 degrees F and line two large, rimmed baking sheets with foil. Place 2 tablespoons olive oil in a small bowl for brushing onto vegetables.
- Remove stems/core tomatoes and slice in half. Heirloom tomatoes are typically wide and flat. They come in different sizes, but are often about the same height. Cut crosswise, instead of from top to bottom for even roasting. Brush both sides of the tomatoes with olive oil and place on the baking sheets, skin side down.
- Cut bell pepper into quarters from top to bottom, then deseed and devein. Brush both sides with olive oil and place on the baking sheets skin side up. Sprinkle tomatoes and peppers with a teaspoon of salt.
- Place the peeled garlic cloves on a piece of foil and drizzle with remaining teaspoon of olive oil. Fold the foil upward to form a pouch and place the pouch onto one of the baking sheets with vegetables.
- Place both baking sheets in the oven. Roast vegetables for 45-50 minutes. Roast garlic for 30-40 minutes.
Prepping Instant Pot
- Roughly chop the basil leaves and set aside.
- Five minutes before the garlic is ready, turn Instant Pot onto low sauté and add ghee and onions. Cook until translucent and just beginning to caramelize, then add roasted garlic and use a spatula to break the garlic up a bit. Stir to combine and cook another 1-2 minutes.
- Turn Instant Pot off and add broth, water, spices, tomato paste, basil leaves, and remaining teaspoon of salt (use less if your broth is salted).
- By now, the vegetables should be done roasting. Remove from oven and carefully transfer tomatoes and peppers to the Instant Pot. Pour any liquid from the baking sheets into the pot as well. Stir to combine, then seal the Instant Pot.
- Set to Manual/High for 10 minutes, allow natural release for 10 minutes, then finish venting manually.
- Remove lid and use an immersion blender to blend to preferred texture, or work in batches to run the soup through a blender.
- Serve immediately with toppings of choice.
Refrigerate in an airtight container for up to 4 days.
Cool completely and freeze in an airtight container for up to 6 months.
Cook time does not include pressurizing and release.
Keywords: INSTANT POT, TOMATO SOUP, HEIRLOOM TOMATOES, TOMATO BASIL SOUP, LOW-CARB, PALEO, GRAIN-FREE, GLUTEN-FREE, SUGAR-FREE, VEGAN