Spicy Mustard Seafood Sauce Recipe – A 5-ingredient Seafood Dipping Sauce for crab legs and shrimp. Plus, it’s gluten free, dairy free, and ketogenic!

Spicy Mustard Seafood Sauce

Dipping Sauce for Seafood

Do you eat more seafood in the summer than any other time of year? We do.

Many types of fish and shellfish are so plentiful in the summer months, it just seems right to strap on a plastic bib and pull out the shell crackers.

Not to mention that summertime is the best time to head out towards the beach for vacation. This crab mustard sauce recipe will be your saving grace when making fresh seafood from home (or your vacation rental!) 

Shrimp, crab and lemon wedges on a platter next to a bowl of yellow sauce.

Seafood Dipping Sauce

We love to steam or grill seafood in the warm season, then serve it with melted butter or creamy sauces.

However, this year I’ve been experimenting with dairy-free seafood dipping options, because our daughter is currently dealing with several food intolerances.

I want her to feel excited about her meals, even though she can no longer consume all the foods the rest of us can eat. Therefore, I’m skipping the classic standbys loaded with dairy and gluten, and using cleaner ingredients with bold flavor.

Making Spicy Mustard Seafood Sauce

Mustard Sauce Recipe

Today’s 5-ingredient Spicy Mustard Seafood Sauce recipe is my absolute new favorite seafood dipping sauce for fresh-caught Dungeness crab and local Carolina shrimp. Yes, we have a popular cocktail sauce recipe that can be used for dunking. However, if you are looking for something unique, this is the seafood sauce for you!

It’s light and perky with a mellow base of gluten-free mayonnaise, a strong tangy note from French’s® Classic Yellow Mustard, and a pop of spicy heat from onions and horseradish.

It’s got a kick, yet does not overpower the fresh sweet flavor of the seafood. Perfection!

French's Classic Yellow Mustard

French’s Classic Yellow Mustard

French’s Classic Yellow Mustard is a summertime staple because it is packed with zesty appeal, and provides a gorgeous sunshine yellow color to recipes.

Yet, did you know it’s also very easy to incorporate into allergy-friendly foods?

Made with only mustard seeds, vinegar, water, and spices, French’s Classic Yellow Mustard is naturally gluten free, dairy free, soy free, nut free, and free of artificial colors and preservatives. Plus, it’s low carb keto fans!

It makes this Spicy Mustard Seafood Sauce a lean, yet tantalizing, addition to all your protein-packed seafood dishes.

Seafood platter with a small bowl of seafood dipping sauce in the middle.

How To Make Seafood Sauce

  1. Start by grating a shallot into fine pieces with a sharp grater.
  2. Add the mayonnaise, French’s Classic Yellow Mustard, Worcestershire sauce, onion, and a scant amount of horseradish to a bowl.
  3. Stir until smooth. Then chill the Spicy Mustard Seafood Sauce until it’s time to serve it.

This will be your new go-to sauce to make with almost any dish (including meats and veggies) to spice up the flavor profile, turning the dish from bland to grand!

Shallot being grated into the mustard sauce.

Seafood Dipping Sauce Ingredients 

This amazing recipe only takes 5 ingredients for endless dipping possibilities:

Seafood dipping sauce ingredients in a bowl before being stirred.

Check the Mustard Seafood Sauce Recipe Card Below to Learn More!

Ingredients needed for mustard seafood dipping sauce.

Ways To Use Seafood Dipping Sauce

Try serving this seafood dip with:

Seafood platter with a mustard seafood sauce in the middle.

Not a fan of seafood?

Serve our mustard dip with:

  • Pork chops
  • Steaks
  • Chicken thighs
  • Baked Ham
  • Roasted Vegetables
  • French Fries
  • As a chip dip
  • Or sandwich spread

Seriously, this “boss sauce” makes everything taste better!

Tip & Tricks

  • Be sure to use prepared horseradish, and not fresh horseradish! If you have horseradish from your garden, you can prepare it for this sauce recipe by grating it and mixing it with a bit of water, white vinegar and salt!
  • For a lighter dip, you can replace the mayonnaise with plain greek yogurt!
  • Don’t forget to serve this mustard sauce with all of your favorite seafood like shrimp!
Mustard seafood dipping sauce in a small bowl on a serving platter with crab.

Frequently Asked Questions

Is mustard sauce good for your health? 

The health benefits of mustard comes mainly from the mustard seeds that are ground into mustard. Mustard seeds provide power-packed omega-3 fatty acids and calcium. They are also known to be antibacterial, antifungal, and even offer anti-inflammatory properties. 

How do you keep this mustard dip?

This mustard should stay in the fridge when not being served. Some mustards can stay at room temperature, however the horseradish in this dish needs to be refrigerated. Place it in an airtight container or jar and refrigerate for up to 3 weeks.

Can I use a different style of mustard? 

Although you can use any mustard in this recipe, classic yellow mustard provides the best color, tang, and spice level that appeals to most people.

Hand dipping crab into a bowl of mustard sauce.

Other Seafood Dishes:

Find more recipes with French’s Mustard on Instagram, Facebook, and Pinterest.

Spicy Mustard Seafood Sauce #GlutenFree #DairyFree #Ketogenic
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Seafood Dipping Sauce Recipe

Prep Time: 5 minutes
Total Time: 5 minutes
Spicy Mustard Seafood Sauce Recipe – A 5-ingredient dipping sauce for crab claws and legs, lobster, and shrimp. Gluten-free, dairy free, and ketogenic! 
Servings: 8 people



  • Grate the shallots with a microplane or cheese grater.
  • Measure all the ingredients and place them in a small mixing bowl.
  • Stir well to combine. Then cover and chill until ready to serve.


Add extra horseradish for a spicier sauce. This dipping sauce is also wonderful on oysters and clams, grilled pork chops, or as a sandwich spread! 


Serving: 1.5tablespoons, Calories: 50kcal, Carbohydrates: 2g, Protein: 0g, Fat: 4g, Saturated Fat: 0g, Cholesterol: 2mg, Sodium: 239mg, Potassium: 25mg, Fiber: 0g, Sugar: 0g, Vitamin A: 15IU, Vitamin C: 0.2mg, Calcium: 5mg, Iron: 0.2mg
Course: Appetizer
Cuisine: American
Author: Sommer Collier
Making this recipe?Follow us on Instagram and tag @ASpicyPerspective so we can share what you’re cooking!

Disclosure: This post is sponsored by French’s Classic Yellow Mustard. All opinions are my own.

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