Low-Carb Crab Melt

This quick and easy, low-carb crab melt sandwich recipe combines creamy, flavorful crab salad and melted cheese on a base of a portobello mushroom. These melts make a satisfying lunch or dinner.

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There is something about melted cheese that turns any sandwich into gooey goodness.  As a kid, sandwiches with melted cheese were synonymous with summer vacations. Toasted cheese sandwiches, grilled ham and cheese sandwiches, and tuna melts were commonly on the summer lunch and dinner time menu. Years later, I discovered crab melts–the upscale, elegant version of the tuna melt. I was instantly in love with the creamy, melty treat.

Crab Melt Prep

Of course, sandwiches are hard to do on a low carb diet. Thankfully, not only does the portobello mushroom make a perfect substitute for bread, but its subtle flavor complements the crab and the cheese.  Portobellos even add to the presentation of the classic crab melt.  These mushrooms piled high with crab salad and melted cheese make a picture-perfect meal suitable for an elegant luncheon.

I pre-bake the mushrooms until they are starting to soften so they are completely tender when the cheese is melted.  This pre-bake is done with the concave side (gill side) down so the juices drip off.  Allowing the juices to drip off helps the mushrooms not get soggy.


Low-Carb Crab Melt

Low-Carb Crab Melt












5 from 1 vote

Low-Carb Crab Melt Sandwiches

This quick and easy, low-carb crab melt sandwich recipe combines creamy, flavorful crab salad and melted cheese on a base of a portobello mushroom.
Servings 4
Author Annissa Slusher


  • 3-4 large portobello mushrooms
  • spray coconut oil
  • salt and pepper to taste
  • 8 ounces lump crab meat
  • 3 tablespoons mayonnaise
  • ½ teaspoon Worcestershire sauce gluten-free, if necessary
  • ½ teaspoon Old Bay Seasoning
  • ¼ teaspoon sea salt
  • dash freshly ground pepper
  • dash cayenne pepper
  • ½ cup finely shredded cheddar cheese quantity divided
  • 1 tablespoon finely chopped parsley
  • 4 green onions thinly sliced


  1. Preheat oven to 375F. Place a rack on a baking dish.
  2. Rinse and dry mushrooms. Remove the gills and stem with a spoon and discard.
  3. Spray mushrooms with coconut oil and lightly season both sides with salt and pepper.
  4. Place mushrooms on the rack with concave side down.
  5. Bake in preheated oven for 7 minutes. Let cool slightly.
  6. In medium bowl, mix crab, mayonnaise, worcestershire sauce, Old Bay, salt, pepper and cayenne until well blended.
  7. Add ¼ cup (reserve the rest) shredded cheese, parsley, and green onions. Stir to combine.
  8. Turn mushroom caps over so the concave side is up and place them back on the baking rack.
  9. Fill mushroom caps with the crab mixture and push down the top of the mound slightly to create a flat surface.
  10. Sprinkle the reserved cheese on top of the crab mixture.
  11. Bake 5-7 minutes or until hot and cheese is melted.

Recipe Notes

Per serving: Calories:201
Fat: 13.1 grams
Carbs: 5.6 grams
Fiber:1.4 grams
Protein: 16.3 grams
Net carbs: 4.2 grams