Equipment
Ingredients
Roasted Vegetables
- 600 g sweet potatoes, peeled and cut into 2cm cubes
- 500 g carrots, peeled and sliced into 2cm rounds
- 30 ml olive oil, divided
- 5 g kosher salt, plus more to taste
Soup Base
- 1 yellow onion, diced
- 3 garlic cloves, minced
- 1200 ml vegetable broth, low sodium
- 15 g fresh tarragon leaves, chopped
- 15 ml lemon juice, freshly squeezed
- black pepper, freshly ground
Nutrition (per serving)
Nutrition is estimated per serving. Nutrients without complete source data are omitted.
Full nutrition
- Calories
- 201 kcal
- Protein
- 4 g
- Carbohydrates
- 36 g
- Fat
- 6 g
- Fiber
- 6 g
- Sugar
- 13 g
- Sodium
- 1414 mg
- Saturated Fat
- 1 g
- Monounsaturated Fat
- 4 g
- Polyunsaturated Fat
- 1 g
- Potassium
- 904 mg
- Calcium
- 116 mg
- Iron
- 2.2 mg
- Magnesium
- 60 mg
- Phosphorus
- 49 mg
- Zinc
- 0.7 mg
- Vitamin A
- 6414 mcg
- Vitamin C
- 14 mg
- Vitamin E
- 1.3 mg
- Vitamin K
- 15 mcg
- Vitamin B6
- 0.2 mg
- Thiamin
- 0.08 mg
- Riboflavin
- 0.06 mg
- Niacin
- 0.9 mg
- Folate
- 21 mcg
- Water
- 99 g
Sources: Aggregated Public Data, USDA FoodData Central
Method
Preheat your oven to 200°C (400°F). Line a baking sheet with parchment paper for easy cleanup.
Toss the cubed sweet potatoes and carrots with 20ml of olive oil and 5g of salt on the baking sheet. Roast for 30-35 minutes, or until the vegetables are tender and edges are beginning to brown.
While vegetables roast, heat the remaining 10ml olive oil in a large pot over medium heat. Add the diced onion and sauté for 5-7 minutes until translucent and soft, but not browned. Add garlic and cook for 1 more minute until fragrant.
Add the roasted carrots and sweet potatoes to the pot. Pour in the vegetable broth. Bring to a boil, then reduce heat and simmer for 10 minutes to allow flavors to meld.
Remove from heat. Transfer the mixture to a blender (in batches if necessary) or use an immersion blender directly in the pot. Blend until completely smooth and velvety. CAUTION: When blending hot liquids in a standard blender, remove the center cap from the lid and cover with a towel to release steam.
Stir in the chopped fresh tarragon and lemon juice. Taste and adjust seasoning with more salt and black pepper if needed. Serve warm, garnished with extra tarragon leaves.
Chef's Notes
- Roasting the vegetables rather than boiling them is the secret to this recipe; it caramelizes the natural sugars and concentrates the flavor, providing a much deeper taste profile.
- Tarragon is potent. Add half the amount first, taste, and then add the rest if you enjoy the licorice notes. It pairs exceptionally well with the sweetness of the carrots.
- This soup is excellent for meal prep. The flavors marry and deepen after sitting in the fridge overnight, making it an ideal make-ahead starter for Thanksgiving.
- Nutritional Bonus: The combination of sweet potatoes and carrots provides over 100% of your daily Vitamin A needs, while the lemon juice adds a hit of Vitamin C to help absorption.
Storage
Refrigerator: 4 days — Flavors improve significantly after 24 hours.
Freezer: 3 months — Freeze without fresh tarragon; add fresh herbs upon reheating.
Reheating: Gently warm over low heat; add a splash of water or broth if thickened.
Troubleshooting
Soup texture is too thick or gluey
Cause: High pectin/starch content in the specific roots used or too much reduction
Fix: Whisk in additional hot vegetable broth or water 50ml at a time until desired consistency is reached
Prevention: Measure liquid ratio carefully
Flavor tastes flat or overly sweet
Cause: Lack of acidity to balance the root vegetables' natural sugar
Fix: Add more lemon juice or a splash of apple cider vinegar in 1 teaspoon increments
Prevention: Taste as you go
Cultural Context
Root vegetable soups are a staple of autumnal harvest cuisine in North America and Europe. The use of sweet potatoes connects the dish to traditional American Thanksgiving flavors, while the inclusion of tarragon (Artemisia dracunculus) introduces a classic French aromatic element, elevating a rustic puree into an elegant first course.
