This is a recipe from the spa cuisine collection of SpaIndex.com: Guide to Day Spas and Stay Spas and was created in connection with the mustard festival held every year in Napa Valley.
The recipe is easy, fast, and rich -- it has an intense taste which is necessary when you are counting calories. As the recipe states, only a tiny bit of the sauce is needed or it's too rich. I used about a tablespoon on my sandwich and although it was delicious, it was too much and I scraped some off. The thin schmear was much better.
I like the idea of using small mushrooms and buns as "mushroom sliders" but for my version, I had a large portabello and a ciabatta roll, so I used those.
This is also an easy but thoughtful sandwich to make for vegetarians which will come in handy this holiday season when everyone else is eating leftover turkey sandwiches. Grill some mushrooms and set them aside for your vegetarian guests so you can make this for them day after Thanksgiving.
Get the entire recipe and tips by clicking the link above. This is my synopsis:
1 mushroom cap, brushed with garlic olive
1 bun, brushed with garlic olive
1 tablespoon of mayo
Splash of lemon juice
Dab of Dijon mustard
handful of chopped basil
salt, pepper, and cayenne
Grill bun and mushroom 4 min each side until cooked. Mix remaining ingredients, top bun with basil mustard sauce, and serve.