Spicy Slow Cooker Beef Roast with Mustard

This mustard roast beef starts with a simple dry rub of mustard powder, garlic, onion, salt and pepper, a quick sear, and a long, slow simmer in beef broth. The result is a juicy, tender and flaky beef roast for dinner.

The slow cooker does almost all the work. Brown the roast in the morning, set it and forget it, and come home to a roast that falls apart with a fork and has a gentle, warm kick from the mustard.

The Best Spicy Mustard Roast Beef (Slow Cooker)

This recipe started with a ‘mystery ingredient’ contest. I had no idea what the ingredient would be! A spice? Some specialty flour? Nuts? I was surprised and excited when I received Colman’s Mustard Powder and Spicy Mustard. I began experimenting and created this slow cooker Beef Roast with Spicy Mustard recipe.

When the contest began, I needed votes, and I even offered voters a free copy of my eBook, 10 Steps on How to Stay Healthy. I’m not above bribing! Thank you to everyone who voted and left a comment on the FB feed. Thank you for voting, my friends!

Mustard powder is the secret here. It is simply ground mustard seed, and it tastes sharp and a little spicy without any of the vinegar tang of jarred mustard. Rubbed onto a chuck roast with garlic powder, onion powder, salt and pepper, it forms a savory crust when the roast hits the hot pan. Then, during hours in the slow cooker, that crust melts into the beef broth and seasons every shred of meat.

Chuck roast is the right cut for this. It has plenty of marbling and connective tissue, which slowly break down in the gentle heat and turn the meat tender and juicy. It’s the kind of easy, hands off dinner that tastes like you worked on it all day. Leftovers make wonderful sandwiches the next day, too.

Why You’ll Love This Mustard Roast Beef

• Only a handful of ingredients. A chuck roast, beef broth, oil and five pantry spices.
• Hands off. A quick sear, then the slow cooker takes over.
• Warm, gentle heat. Mustard powder adds a little spice without overpowering the beef.
• Tender and flaky. Hours of slow cooking make the roast juicy and easy to shred.

Ingredients You’ll Need

Exact amounts are in the recipe card below.

• Chuck beef roast: A 3 pound roast, fully thawed. Chuck is a well marbled, hardworking cut, which makes it tough if cooked quickly but meltingly tender after hours in the slow cooker. Make sure it’s completely thawed so it sears well and cooks evenly. Pat it dry with paper towels so the rub sticks and the outside browns nicely.
• Colman’s mustard powder: The star ingredient. Dry mustard gives a sharp, spicy warmth that blooms as it cooks. Any brand of ground mustard works, but Colman’s is the one this recipe was created with. Look for it in the spice aisle in a small yellow tin.
• Salt and pepper: Season the beef all the way through. A large roast needs a good amount of salt to taste seasoned. Since canned broth also contains salt, taste the cooking liquid at the end before adding more.
• Garlic powder and onion powder: Add savory depth to the rub. Powders stick to the surface of the roast and won’t burn the way fresh garlic can in a hot pan.
• Coconut or olive oil: For searing. Either one works. Heat it until it shimmers so the roast browns instead of steaming. Refined coconut oil has no coconut flavor, so it won’t change the taste of the beef.
• Beef broth: One 15 ounce can. It surrounds the roast with flavorful liquid, keeps the meat moist and becomes a rich, mustardy cooking liquid you can spoon over each serving.

Half of the spice mix goes on the roast before searing, and the other half goes into the slow cooker with the broth. That way the crust is seasoned and the cooking liquid is too, so the flavor carries all the way through the beef.

How to Make Mustard Roast Beef

1. Mix the rub. Place the roast on a flat surface. In a small bowl, combine the mustard powder, salt, pepper, garlic powder and onion powder.
2. Season the roast. Sprinkle half of the spice mixture evenly over the roast and pat it on so it sticks.
3. Sear. Heat the oil in a large skillet over medium heat until it shimmers. Add the roast and brown it for about 1 minute on each side, until it has a deep golden crust and smells toasty.
4. Load the slow cooker. Transfer the roast and any pan drippings to a large slow cooker. Pour the remaining spice mixture and the beef broth over the roast. Scrape any browned bits from the skillet into the slow cooker too, since they’re packed with flavor.
5. Cook low and slow. Cook on HIGH for 6 hours or on LOW for 9 to 10 hours, until the roast is fork tender and pulls apart easily.
6. Check for tenderness. If your roast beef is still tough, cook it for an additional hour. Tough chuck roast almost always just needs more time.
7. Serve. Let the roast rest for a few minutes, then slice or shred it with two forks and spoon some of the cooking liquid over the top.

Ways to Customize Mustard Roast Beef

• Add vegetables. Tuck potatoes and carrots around the roast, like in this Slow Cooker Roast Beef, Potatoes, and Carrots.
• Make sandwiches. Pile shredded beef on toasted rolls with a little spicy mustard.
• Serve it over something cozy. Mashed potatoes, rice or egg noodles soak up the mustardy cooking liquid.
• Adjust the heat. Use a little less mustard powder for a milder roast, or a little more for extra kick.

Mustard Roast Beef FAQs

• What cut of beef should I use? A chuck roast. Its marbling breaks down during slow cooking and keeps the beef juicy.
• Can I use prepared mustard instead of mustard powder? The recipe was built around mustard powder, which gives a cleaner, spicier flavor. Prepared mustard adds vinegar tang and will change the taste.
• Is this roast very spicy? No. Mustard powder gives a gentle warmth, not a lot of heat. The sharpness mellows even more during the long, slow cook.
• Should I cook on HIGH or LOW? Either. HIGH takes about 6 hours and LOW takes 9 to 10 hours. LOW is handy for long workdays.
• Why is my roast still tough? It needs more time. The connective tissue in chuck has to fully break down, so cook it for an additional hour and check again.
• Can I use a different roast? Chuck is best. Leaner cuts like round or sirloin roasts work but will be less juicy and won’t shred as easily.
• How do I store leftovers? Refrigerate the beef in some of its cooking liquid in an airtight container for 3 to 4 days.
• Can I freeze it? Yes. Freeze shredded beef with a little cooking liquid for best quality up to about 3 months, and thaw it in the fridge.

Roast Beef with Spicy Mustard

Mustard roast beef is a chuck roast rubbed with Colman's mustard powder, garlic, onion, salt and pepper, seared, then slow cooked in beef broth. It turns out juicy, tender and flaky with a gentle mustard kick.

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Ingredients

  

• 3 lb chuck beef roast thawed
• 2 tsp Colman's mustard powder
• 1 tsp salt
• 1 tsp pepper
• 1 tsp garlic powder
• 1 tsp onion powder
• 2 Tbs coconut or olive oil
• 1 can 15 oz organic beef broth

Instructions

 

• Place roast on flat surface. In a small bowl, combine mustard powder, salt, pepper, garlic powder, and onion powder. Sprinkle half of mixture evenly over roast.
• Meanwhile in a large skillet, heat oil over medium heat. Add roast and brown for approximately 1 minute on each side. Transfer roast and contents to large slow cooker. Pour remaining mustard powder mixture and beef broth over roast.
• Cook on HIGH for 6 hours or on LOW for 9 to 10 hours. If your roast beef is still tough, cook for an additional hour.

Made this roast beef? Leave a star rating in the recipe card and tell me how it turned out in the comments below. I love hearing how you served it.

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