This slow cooker spring leek Dijon chicken is one of those cozy, low-effort dinners that feels a little special without asking much of you. Everything starts with one simple mixture: sliced leeks, Dijon mustard, white wine, a splash of heavy cream, and fresh tarragon. You just drizzle it over raw chicken breasts in the slow cooker, turn it on, and let the house fill with that comforting, bistro-style aroma. It has a gentle, springy flavor that’s family-friendly but still interesting enough for company, and it’s perfect for busy days when you want dinner to quietly take care of itself.
Serve the chicken with plenty of the creamy leek sauce spooned over the top. It’s especially good over mashed potatoes, buttered egg noodles, or simple white or brown rice to soak up all the juices. Add a green vegetable on the side—steamed green beans, roasted asparagus, or a simple salad with a light vinaigrette all work well. Warm crusty bread or dinner rolls are nice for mopping up the extra sauce, and if you’re serving adults, a glass of the same dry white wine you used in the recipe ties everything together.
Slow Cooker Spring Leek Dijon Chicken
Servings: 4

Ingredients
2 pounds boneless, skinless chicken breasts (about 4 medium)
1 1/2 cups sliced leeks (white and light green parts only, well rinsed)
2 tablespoons Dijon mustard
1/2 cup dry white wine
1/2 cup heavy cream
2 tablespoons chopped fresh tarragon (plus extra for garnish, optional)
2 tablespoons olive oil (or melted butter)
2 cloves garlic, minced
1 teaspoon kosher salt, divided
1/2 teaspoon black pepper, divided
1/2 teaspoon dried thyme (optional, for extra herby flavor)
1 teaspoon cornstarch (optional, for thicker sauce)
1 tablespoon cold water (optional, to mix with cornstarch)
Directions
Prepare the slow cooker: Lightly grease the bottom of your slow cooker crock with a little olive oil or nonstick spray to help prevent sticking and make cleanup easier.
Season the chicken: Pat the chicken breasts dry with paper towels and place them in a single layer in the bottom of the slow cooker. Sprinkle about 1/2 teaspoon of the salt and 1/4 teaspoon of the pepper evenly over both sides of the chicken.
Slice and rinse the leeks: Trim off the dark green tops and root ends of the leeks. Slice the white and light green parts into thin half-moons. Place the sliced leeks in a bowl of cool water, swish them around to loosen any dirt, then lift them out with your hands or a slotted spoon and drain well.
Mix the 1 mixture: In a medium bowl, whisk together the sliced leeks, Dijon mustard, white wine, heavy cream, chopped fresh tarragon, olive oil, garlic, remaining 1/2 teaspoon salt, remaining 1/4 teaspoon pepper, and dried thyme if using. Stir until the mustard and cream are well combined and the leeks are coated. This is your 1 mixture that you’ll drizzle over the chicken.
Drizzle the 1 mixture over the chicken: Holding the bowl over the slow cooker, carefully drizzle the entire leek–Dijon–wine–cream–tarragon mixture evenly over the raw chicken breasts. Use a spoon or your hands to spread the leeks so they’re nestled around and on top of the chicken. The chicken should be mostly covered with the creamy mixture and leeks.
Cook the chicken: Cover the slow cooker with the lid. Cook on LOW for 3 1/2 to 4 1/2 hours, or until the chicken is cooked through and reaches an internal temperature of 165°F. Try not to lift the lid too often so the heat stays consistent.
Optional – thicken the sauce: If you’d like a slightly thicker sauce at the end, whisk the cornstarch and cold water together in a small bowl to make a slurry. Remove the cooked chicken breasts to a plate and cover them loosely with foil. Stir the cornstarch slurry into the hot leek sauce in the slow cooker, cover, and cook on HIGH for 10 to 15 minutes until slightly thickened, stirring once or twice.
Finish and serve: Taste the sauce and adjust seasoning with a pinch more salt or pepper if needed. Return the chicken to the slow cooker, spoon some of the sauce and leeks over the top, and let it sit on WARM for a few minutes to soak up flavor. Serve the chicken topped generously with the creamy leek and tarragon sauce, garnishing with extra fresh tarragon if you like.
Variations & Tips
For picky eaters, you can reduce the Dijon mustard to 1 tablespoon and add 1 tablespoon of honey for a milder, slightly sweeter sauce. If leeks are a hard sell, swap half of them for thinly sliced sweet onion so the flavor is more familiar. For kids who don’t like visible herbs, leave the fresh tarragon leaves larger so adults can pick them out and sprinkle on their own plates, or stir in 1 teaspoon dried parsley instead for a softer flavor. To make it a bit lighter, use half-and-half instead of heavy cream, understanding the sauce will be a touch thinner. If you prefer to skip wine, substitute low-sodium chicken broth plus 1 teaspoon lemon juice for brightness. For a one-pot style meal, scatter 1 pound of baby potatoes (halved) in the bottom of the slow cooker before adding the chicken, then drizzle the same 1 mixture over everything and cook as directed. You can also use boneless, skinless chicken thighs instead of breasts; they stay very tender and can handle an extra hour on LOW if needed. To change it up from week to week while keeping the same easy drizzle method, try swapping tarragon for fresh thyme or basil, or stir in a handful of frozen peas during the last 20 minutes of cooking for a pop of color and sweetness.