Pot Red Lentil Soup

This red lentil soup is a comforting meal that comes together quickly in the Instant Pot. Perfect for busy evenings when you want something hearty, warm, and nourishing without much fuss.

I first made this after spotting red lentils on sale and now it’s a favorite weeknight staple. The soup is so smooth and cozy I reach for it whenever I want something filling but light.

Ingredients

• 1½ cups dry red lentils: rinsed for a clean, smooth texture and to remove any debris
• 1 tablespoon oil: optional for sautéing adds richness but can be swapped for water or broth for oil-free cooking
• 1 large yellow onion: chopped for a sweet, savory flavor base that softens during cooking
• 4 large cloves garlic: minced for pungent, aromatic depth
• 2 teaspoons dried tarragon: offers a subtle anise-like flavor that brightens the soup
• ¾ teaspoon dried thyme: adds earthiness balancing the lentils
• ⅛ teaspoon poultry seasoning blend: or a pinch of sage gives a hint of warmth and complexity
• ¼ teaspoon black pepper: adjusted to taste adds mild heat
• 1 small lemon: halved giving fresh acidity to brighten and balance flavors
• 4½ cups water: the cooking liquid to cook lentils until tender
• ¾ teaspoon fine sea salt: enhances all the flavors

Instructions

Build The Flavor Base:

Cook the chopped yellow onion in the Instant Pot on saute mode with oil for 7 to 8 minutes until softened and translucent. This slow cooking develops sweetness essential to a rich broth. Stir occasionally so nothing sticks or burns.

Add Aromatics And Spices:

Add minced garlic, tarragon, thyme, poultry seasoning, and black pepper. Stir constantly for about 1 minute until fragrant. Squeeze in a little lemon juice and scrape the bottom of the pot to deglaze and capture any browned bits to deepen flavor. Turn off saute.

Add Lentils And Cook:

Add the rinsed red lentils, water, and salt. Stir it all together then lock the Instant Pot lid and seal the vent. Set to cook at high pressure for 8 minutes. When finished carefully perform a quick pressure release by flipping the vent knob.

Finish And Puree:

Remove the lid and let the soup rest a few minutes to cool slightly. Using an immersion blender, puree the soup until completely smooth and creamy. Taste and adjust salt, pepper, and lemon juice to brighten. Serve hot and enjoy.

My favorite ingredient here is the tarragon which I don’t use enough of, but its subtle floral note lifts the earthy lentils beautifully. I remember my grandmother making lentil soup but never adding lemon—once I did it changed the whole game and made the flavors pop.

Storage Tips

Store leftovers covered in the refrigerator up to 4 days. Reheat gently on the stovetop adding a splash of broth or water if it thickens too much. You can also freeze in airtight containers for up to 3 months and thaw overnight in the fridge before warming.

Ingredient Swaps

You can swap yellow onion for shallots or sweet onions for a milder flavor. Replace tarragon with fresh basil or oregano for a different herb note. Use vegetable broth instead of water for a richer, savory soup base. Skip poultry seasoning and increase thyme for a simpler profile.

Serving Ideas

Serve this soup with warm crusty bread or pita for dipping. Add a dollop of plain yogurt or a sprinkle of fresh herbs like parsley or cilantro on top for a fresh contrast. It pairs well with a light salad for a complete meal.

The quick lemon squeeze is essential for the final flavor balance so never omit it, even just a small bit makes a big difference. Once you make this a couple of times you’ll find your perfect seasoning balance with salt and pepper so trust your palate.

Frequently Asked Recipe Questions

→ Can I make this soup oil-free?

Yes, for an oil-free version, replace the oil with a splash of water or broth when sautéing the onions to prevent sticking.

→ What does the poultry seasoning add to this dish?

The poultry seasoning blend provides a subtle earthy warmth and herbaceous notes, complementing the thyme and tarragon.

→ How do I achieve a creamy texture without cream?

Pureeing the cooked lentils with an immersion blender creates a naturally creamy consistency without the need for dairy.

→ Can I adjust the seasoning to suit my taste?

Absolutely, you can increase or decrease black pepper and salt levels, and add more lemon juice to brighten the flavors.

→ What type of lentils is best for this dish?

Red lentils work best as they cook quickly and break down smoothly, contributing to the soup’s creamy texture.

→ Is it necessary to rinse the lentils before cooking?

Rinsing the lentils removes any dust or impurities and helps achieve a cleaner flavor and appearance.