Slow Cooker Chicken Breast With Creamy Mustard Leek Sauce Recipe

Jessica Published April 28, 2020

Tired of the same old frying, roasting and grilling methods to cook your chicken? Cooking with the same method can be boring, as if there’s no other way you can get creative with your food. If you’re looking for a healthy option that isn’t bland or boring then you can bring it up to a twist with our classic Slow Cooker Chicken Breast With Creamy Mustard Leek Sauce – an ideal dinner dish to end the day on a delicious note. Check out our other slow cooker recipes after enjoying cooking this great dish. If you’re a fan of chicken meat like in our slow cooker chicken recipe, then have a look at our chicken recipes for ideas. 

How To Make Slow Cooker Chicken Breast With Creamy Mustard Leek Sauce

0 from 0 votes
An easy-to-follow chicken dish that’s healthy and hearty to enjoy. Be ready to savor the flavor of the creamy sauce and the tender chicken - a worthy dish in every bite. 
30 mins
150 mins
180 mins


  • 1 Small mixing bowl
  • 1 Whisk
  • 1 Plastic wrap
  • 1 Slow-Cooker
  • 1 Spoon
  • 1 Cooking Pot
  • 1 Tongs
  • 1 Strainer
  • 1 Cast-iron skillet or cooking pan



  • 2 Chicken Breast boneless and skinless
  • cup Mayonnaise
  • ½ tbsp Salt
  • 1 tbsp Sage finely minced
  • 2 tbsp Cider vinegar


  • 1 Shallot finely minced
  • 1 Leek trimmed, cut and sliced into half moons
  • ¾ cup Chicken Stock
  • tbsp Salt
  • 1 tbsp Corn Starch
  • 2 tbsp Whole Grain Mustard
  • 1/3 cup Heavy Cream
  • 340 g Egg Noodles
  • 3 tbsp Butter
  • 1 tbsp Chives chopped



  • In a small mixing bowl combine mayonnaise, ½ tbsp salt, sage, and cider vinegar. Whisk these ingredients together until it becomes a smooth consistency.
  • Nestle chicken breasts on both sides into the mixture until coated. Get a cling wrap and cover the mixing bowl. Have this refrigerated overnight so that the chicken locks in the flavors of the mixture.


  • Prepare the ingredients before cooking the Slow-Cooker Chicken Breast With Creamy Mustard Leek Sauce. Have them set aside for easier reach.
  • In the slow-cooker, drop in your shallots, leek, chicken stock, cornstarch, and heavy cream. Using a spoon, mix these ingredients together before adding in the marinated chicken breasts.
  • When that’s done, cook the marinated chicken breasts into the mix for 2 hours and 30 minutes with a temperature of 165 degrees Fahrenheit. Set the slow-cooker to HIGH. Check in on the chicken every 15-20 minutes to make sure it doesn’t dry out.
  • For the meantime, ready your egg noodles ready by adding it into the cooking pot with boiling water. Cook egg noodles until soft -  you can try getting a strand and tasting it to know if it’s good to go. Once you’re done, drain your egg noodles in a strainer.
  • Next, prepare the cast-iron skillet and melt in the butter. Keep an eye on the butter and make sure it doesn’t burn before adding in the egg noodles. Toss your egg noodles into the butter and using your tongs, mix it in until the butter coats the pasta.
  • Once you have your chicken and egg noodles ready, it’s time to plate. Start by placing your buttered egg noodles onto a clean plate. Take out your chicken breasts and slice it into medallion shaped pieces. Top it over the egg noodles along with the creamy mustard leek sauce.
  • Finish it with some chives to garnish. And there you have it, a creamy chicken dish that’s bursting with flavor in every bite.

Recipe Notes

In making this recipe, never go ahead without making sure you have all the ingredients made available, that way it’s easier to follow this recipe and gives you less cooking time. 
Remember, it takes the chicken breast overnight to marinate in your mixture. This tenderizes the meat, so it soaks up the flavors from the sauce. Marinating it in a few hours will only give your dish so little to taste and you might end up with a dry and tasteless dish.
Aside from chicken breasts, feel free to try other chicken parts when making this dish. However, you would need to make adjustments to the cooking time in the slow cooker to avoid dry cooked chicken. 

Nutrition Facts

Calories: 1556kcal | Carbohydrates: 139g | Protein: 78g | Fat: 75g | Saturated Fat: 28g | Cholesterol: 406mg | Sodium: 3193mg | Potassium: 1518mg | Fiber: 8g | Sugar: 8g | Vitamin A: 2096IU | Vitamin C: 10mg | Calcium: 156mg | Iron: 6mg

Commonly Asked Questions

How long should you cook chicken in the crockpot?

In an internal temperature of 165 degrees Fahrenheit, if you’re cooking chicken at LOW, then cooking time should take you about 4 to 5 hours. If you’re cooking on HIGH, it shortens cooking time to 2 to 3 hours. Always check on your chicken every 15-20 minutes just to be sure it’s not overcooked.

Can you overcook chicken in a slow cooker?

Yes, there is a probability that chicken may come out dry and overcooked when not monitored properly. Always follow the recommended cooking times to avoid instances, but it’s also good to check up on now and then for a juicy and tender outcome.


This savory dish is perfect if you’re having a home-cooked meal for a dinner date or if you’re having a couple of friends come over. It’s easy to follow and tastes delicious. If you’re planning on making this for a bigger group of people, check how many servings you’ll need to make - if you need to double or triple the number of ingredients to pull it off.

Since this dish takes a longer time in the actual cooking time, never rush it or you’ll end up with a bad tasting dish. Cook this when you have the time to spare so that your dish comes out like it’s made from a 5-star restaurant.



A food blogger with a strong passion for all thing delicious. Being able to take a simple ingredient and transform it into something complex and delectable brings me joy. It is my mission to show you how to do the same with the simple ingredients that you have on hand. Learn how to make restaurant-worthy meals, on a budget, and right at home!

Leave a comment