There’s a certain kind of magic that happens when you walk through the front door after a long day and the air is thick with the scent of tarragon, sweet leeks, and slow-simmered chicken. It’s the aroma equivalent of a weighted blanket—warm, herbal, gently sweet, and instantly grounding. I developed this Slow Cooker Chicken and Leek Soup with Tarragon last February when the Pacific Northwest was in its usual month-long drizzle fest and every inch of me craved something cozy that didn’t require standing over the stove. My slow cooker had been collecting dust on the top shelf, but one farmers-market bouquet of leeks later, this soup was born.

What I adore about this recipe is how it straddles the line between “rustic Sunday supper” and “elegant enough for company.” The tarragon lends a faint anise note that makes guests ask, “What is that lovely flavor?” while the leeks melt into silky ribbons that practically dissolve on your tongue. Bone-in thighs keep the meat juicy, and a splash of dry white wine added in the final hour gives the broth a restaurant-worthy depth. Serve it with a crusty baguette and a crisp green salad, or ladle it over cauliflower mash for a low-carb twist. Either way, it’s the kind of meal that feels like a gentle exhale—exactly what winter (or a chaotic week) demands.

Why This Recipe Works

Hands-off dinner: Dump, set, forget—come home to perfection.
Layered flavor: Leeks caramelize slowly while tarragon infuses the broth.
Protein-rich & light: 32 g protein per serving yet under 400 calories.
One-pot comfort: No extra pans—everything cooks in the ceramic insert.
Freezer-friendly: Doubles beautifully; freeze half for a rainy day.
Low-carb & gluten-free: Naturally fits most dietary needs.
Fridge clean-out: Use leftover rotisserie chicken or sad celery.

Ingredients You'll Need

Great soup starts at the grocery store. Look for leeks with firm white and pale-green stalks and no slimy spots—about 1½ inches diameter is the sweet spot for tenderness. If they’re pencil-thin, they’ll vanish into nothing; if they’re club-size, the inner core can be woody. Give them a good rinse under cold water after slicing; nobody wants gritty soup.

Chicken thighs: Bone-in, skin-on is non-negotiable for collagen-rich body. Swap drumsticks if they’re on sale, but avoid boneless breasts—four hours on low will turn them into sawdust. Organic air-chilled thighs have the cleanest flavor.

Tarragon: Fresh tarragon is worth splurging; dried tarragon loses its haunting perfume within months. If you must substitute, use 1 tsp dried for every 1 Tbsp fresh, but add it in the last 30 minutes to preserve what little essential oil remains.

White wine: A dry, unoaked Sauvignon Blanc or Pinot Grigio brightens the broth without sweetness. No wine? Replace with ½ cup chicken stock plus 1 Tbsp white-wine vinegar for a similar acidic pop.

Baby potatoes: I leave the skins on for rustic texture and extra potassium. If you prefer a lower-carb bowl, substitute one head of roughly chopped cauliflower and reduce cook time by 30 minutes.

Cream finish: Just ¼ cup of heavy cream whisked in at the end gives the illusion of richness without turning the soup into chowder. Coconut milk works for dairy-free, though it will add faint sweetness.

How to Make Slow Cooker Chicken And Leek Soup With Tarragon

Prep the leeks & aromatics

Trim the root ends and dark-green tops from 3 large leeks, leaving the pale-green and white parts. Halve lengthwise, then slice crosswise ½-inch thick. Transfer to a bowl of cold water and agitate to release grit; lift into a colander to drain. Pat dry with kitchen towels. Dice 2 medium carrots and 2 celery stalks into ¼-inch pieces; set aside.

Sear the chicken (optional but flavor-boosting)

Heat 1 Tbsp olive oil in a heavy skillet over medium-high. Season 6 bone-in, skin-on chicken thighs with 1 tsp kosher salt and ½ tsp black pepper. Sear skin-side down 3 minutes until golden; flip 1 minute more. Transfer to slow cooker. Deglaze skillet with ½ cup of the wine, scraping browned bits; pour into cooker.

Layer vegetables & seasonings

Scatter leeks, carrots, and celery over chicken. Add 1 lb baby potatoes, 3 cloves minced garlic, 2 bay leaves, 1 tsp kosher salt, ½ tsp black pepper, and 4 cups low-sodium chicken stock. Resist stirring—keeping layers helps the chicken stay above the liquid so it steams rather than boils.

Set it & forget it

Cover and cook on LOW 4 hours or HIGH 2 hours until chicken registers 175 °F and potatoes are fork-tender. If you’re away 8–9 hours, use the LOW setting; the chicken will fall-off-the-bone tender and the leeks will caramelize deeper.

Shred the chicken

Use tongs to transfer chicken to a plate; discard skin and bones. Shred meat into bite-size pieces with two forks. Skim excess fat from the surface of the soup using a wide spoon or ladle.

Finish with tarragon & cream

Return shredded chicken to cooker. Stir in remaining ¼ cup wine, 3 Tbsp chopped fresh tarragon, 2 tsp Dijon mustard, and ¼ cup heavy cream. Cover and cook on HIGH 15 minutes more to bloom flavors. Taste and adjust salt.

Serve & garnish

Ladle into warm bowls. Top with extra tarragon leaves, a crack of black pepper, and a drizzle of good olive oil. Pass crusty bread for sopping up the herb-flecked broth.

Expert Tips

Overnight Prep

Chop leeks, carrots, and celery the night before; store in a zip bag with a damp paper towel to prevent drying.

No-Wine Option

Sub with ½ cup chicken stock + 1 Tbsp lemon juice for brightness without alcohol.

Rapid Chill

Transfer soup to a shallow metal pan; refrigerate 30 minutes, then portion into freezer bags laid flat for quick thawing.

Double Batch

Use a 7-qt cooker; freeze half in muffin trays for single-serve portions that reheat in 90 seconds.

Variations to Try

Summer Garden Edition: Swap potatoes for 2 cups fresh corn kernels and 1 cup diced zucchini; add in last 30 minutes.
Mushroom & Thyme: Replace tarragon with 2 tsp fresh thyme and fold in 8 oz sautéed cremini mushrooms.
Spicy Kick: Add 1 minced jalapeño and ½ tsp smoked paprika; finish with a swirl of chipotle crema.
Vegan Twist: Substitute 2 cans chickpeas for chicken, use coconut milk, and swap stock for vegetable broth.

Storage Tips

Refrigerator: Cool completely, transfer to airtight containers, and refrigerate up to 4 days. The flavors meld beautifully overnight, making leftovers even better.

Freezer: Ladle cooled soup (minus potatoes if you dislike texture change) into quart-size freezer bags, label, and freeze flat up to 3 months. Thaw overnight in the fridge or 5 minutes under lukewarm water, then reheat gently.

Reheating: Warm on the stove over medium-low, stirring occasionally, until 165 °F. Add a splash of stock if thickened. Microwave works in 60-second bursts, stirring between.

Make-ahead: Slice leeks and dice vegetables on Sunday; store in separate containers. Morning of, dump everything into the slow cooker and hit start—dinner is solved.

Frequently Asked Questions

Boneless thighs work in a pinch, but reduce cook time to 3 hours on LOW; longer and they’ll shred into mush. Breasts dry out—avoid them.

Slice first, then rinse. Submerge in a bowl of cold water, swish vigorously, and let grit sink. Lift leeks out with your fingers, leaving sand behind.

Absolutely. Simmer covered 45–60 minutes until chicken is tender; add tarragon and cream in the last 5 minutes.

Culinary amounts are generally safe; therapeutic doses of tarragon supplements are not recommended. Consult your doctor if concerned.

Yes, provided your slow cooker is 7 qt or larger. Increase cook time by 30 minutes on LOW to ensure potatoes soften.

A crusty sourdough or seeded whole-grain boule stands up to the hearty broth. Warm in the oven 5 minutes for that fresh-baked aroma.

Slow Cooker Chicken And Leek Soup With Tarragon

Why This Recipe Works

Ingredients You'll Need