Yes, I have a fondness of gooey cheese, sweet caramelized onions and earthy mushrooms. All three have been a consistent staple in my life since childhood. I use them in burgers, on pizza, in quesadillas and hot sandwiches. You name it, I’ve probably tried it. So, I thought why not on a biscuit tart? Much to my surprise, they came out great! I love the bite of citrus from the white wine and Cajun mustard. It seems to pull it all together.
1 tbs unsalted butter
8 small yellow onions, halved and thinly sliced
Olive oil and water
1 tbs unsalted butter
16 medium sized button mushrooms, sliced
Salt and pepper to taste
1 can flaky layer butter biscuits
8 slices gruyere cheese
2 tsp unsalted butter
2 tsp shallot, minced
1 c dry white wine
1 tsp Creole mustard
½ c heavy cream
1 tsp dried thyme
Salt to taste
Preheat oven to 350˚
In a large sauté pan melt 1 tbs. Add onions and cook on low heat for 1-1 ½ hours, stirring periodically. You will need to add olive oil and water, alternating, 1 tsp at a time as needed so your onions don’t burn. (yes, you can add water, we do this a lot in the restaurants when cooking down caramelized onions and it works great) Cook them until they are a beautiful golden brown and have reduced in size significantly. When your onions look like they are close to getting done, add 1 tbs butter to a separate pan and melt over medium high heat. Add mushrooms and cook down until tender. Before removing from heat, add salt and pepper to taste. Use a slotted spoon to remove mushrooms and set aside in a colander. Reserve mushroom liquid, you will be using it as a base for the sauce later.
Meanwhile, prepare the biscuit tarts by arranging them on a nonstick sheet pan making sure to leave 1-2 inches between. Gently press the center of each biscuit, creating a well for the filling. Top each biscuit with 1 slice of gruyere cheese. Arrange mushrooms in a pinwheel shape on top of the cheese. Top mushrooms with two heaping tablespoons of caramelized onions. Make your egg wash by lightly whisking together 1 egg and 1 tsp water. Brush edges of each biscuit with egg wash and bake for 30-40 minutes or until the edges are golden brown.
While biscuits are cooking, make your cream sauce. Heat reserved mushroom liquid from your Gruyere tarts over medium high heat and bring to a simmer. Add 2 tsp butter and shallots. Cook until liquid has almost evaporated. Deglaze with wine and mix in mustard. Whisk in cream, thyme and salt to taste.Once biscuits and sauce are done, spoon sauce over the tops of your tarts and serve immediately.