Slow Cooker Red Lentil Pumpkin Soup

Updated November 13, 2025

Introduction

A comforting, nutrient-dense soup perfect for cool weather, this slow-cooker recipe combines tender red lentils with creamy pumpkin purée, spiced with turmeric, smoked paprika, and cumin. Topped with toasted pepitas, it offers a balanced mix of earthy, sweet, and savory flavors, ideal for weeknight meals or weekend gatherings.

Total Time

• 4 hours (active prep time: 15 minutes)

Ingredients

Lentils & Base

• 1½ cups red lentils (rinsed and drained)

• 1 (15-ounce) can pumpkin purée (or 1½ cups roasted butternut squash puree)

• 5 cups water (for cooking)

Spices & Aromatics

• 1 teaspoon ground turmeric

• 1 teaspoon smoked paprika

• 1 teaspoon ground coriander

• ½ teaspoon crushed red pepper flakes (optional)

• ¼ teaspoon ground cinnamon

• ½ teaspoon cumin seeds

• 1 red onion (chopped, 1 cup)

Fats & Seasonings

• 4 tablespoons olive oil, divided

• 1 tablespoon Kosher salt (adjust to taste)

• 1 lemon (juiced and zested, optional)

Toppings

• ½ cup pepitas (pumpkin seeds, unsalted preferred)

Instructions

Step 1: Cook the Lentil-Pumpkin Base

1. In a 6- to 8-quart slow cooker, combine the red lentils, pumpkin purée, turmeric, smoked paprika, ground coriander, crushed red pepper (if using), cinnamon, 1 tablespoon olive oil, and 1 tablespoon Kosher salt.

2. Add 5 cups of water and stir gently to ensure even distribution.

3. Set the slow cooker to high heat and cook for 4 hours, or low heat for 6 hours, until the lentils are tender and the soup base thickens slightly. Note: The soup will hold on warm for up to 4 hours if needed.

Step 2: Toast Pepitas & Sauté Onion

• Toast Pepitas: While the soup cooks, heat 1 tablespoon olive oil in a small skillet over high heat. Add the pepitas, cumin seeds, and a pinch of salt (if pepitas are unsalted). Stir constantly until the pepitas are golden and fragrant, and cumin seeds sizzle/pop (2–3 minutes). Transfer to a paper towel-lined plate to cool.

• Sauté Onion: In the same skillet (wipe clean if needed), heat the remaining 2 tablespoons olive oil. Add the chopped red onion and a generous pinch of salt. Cook over medium-high heat (stir frequently to prevent burning), until deeply browned and caramelized (8–10 minutes).

Step 3: Finish the Soup

1. Once the lentils are tender, remove the slow cooker from heat. Add the caramelized onion, its oil, lemon juice (and zest, if using), to the soup. Stir well to combine.

2. Taste and adjust salt to preference.

Step 4: Serve

Ladle the soup into warmed bowls. Top with toasted pepitas. If the soup thickens excessively (it will as it cools), add ¼–½ cup water to reach desired consistency.

Chef’s Tips

• Lemon Zest: Zest the lemon before juicing to add bright, aromatic layers.

• Budget Swap: Use garden-harvested butternut squash: roast 15–18 oz peeled squash at 400°F for 30 minutes, scoop flesh, and puree.

• Protein Boost: Add 2 bone-in, skin-on chicken legs to the slow cooker in Step 1 (increase cooking time by 30 minutes if using raw chicken).

• Greens Addition: Stir in 1 cup chopped baby arugula or spinach in Step 3 for nutrition and texture.

• Salt Adjustment: If overly salty, dilute with water or add a splash of unsweetened plant milk (soy milk works well).

Customer Reviews

• "Terrific and easy! I zested the lemon (a habit from Ruffage cookbook) and added it for extra brightness. Sautéed onions on medium-high to caramelize, not blacken. Arugula next time!"

• "Budget-friendly and unique—pantry staples only. Perfect for rainy days!"

• "Used 20 garden butternut squash: roasted and pureed, worked beautifully."

• "Added chicken legs for a carnivorous family—success!"

• "Too salty! Reduce salt to 1 tsp, add soy milk to balance. Still hearty."

• "Frozen pumpkin chunks + extra spinach. Only 1 onion was too little; add 2 next time."

Happy cooking! 🍲