Maybe it’s just me, but I am obsessed with mushrooms. It’s one of those ingredients that I seek out because there are so many varieties. Whether I’m at a restaurant scoping out the menu items or at my local farmers' market, I make it a point to try a new mushroom variety every chance I get.

From the everyday portobello caps to the high-end and uber expensive morels and truffles, this fungi is an ingredient that transcends any social status, because not only can a poor college student afford it, but the richest person in the world would be drawn to it.

For this recipe, I was personally inspired by the classic French onion soup and the seasonal mushrooms that I bought from the farmers market. Considering the fact that I can’t bake but still want to make sure that anything I make will immediately initiate one’s salivary glands, I cheated a little and used store-bought puff pastry for this recipe.

Combining the mushroom’s natural earthiness with the sweetness from the caramelized onions and the underlying richness from the Gruyère base makes this the perfect dish to highlight one of my favorite ingredients.

 #SpoonTip: You can use this recipe with any other seasonal ingredients you find at the market too. Just prep the ingredients and begin the recipe at Step 6. Some ideas include: 1) rosemary, potato and bacon, 2) maple, butternut squash and pecans, 3) heirloom tomato and basil. 

Mushroom and Caramelized Onion Tart

  • Prep Time:15 mins
  • Cook Time:45 mins
  • Total Time:1 hr
  • Servings:4
  • Medium


  • 2 puff pastry sheets
  • 32 ounces mushrooms
  • 3 yellow onions sliced
  • 1 1/2 cups Gruyère cheese
  • 2 cloves garlic minced
  • 3 tablespoons unsalted butter
  • Parmesan cheese
  • thyme
  • olive oil
  • balsamic vinegar
  • salt
  • pepper
chocolate, sweet, candy
Alex Vu
  • Step 1

    Preheat oven to 400°F. Keep the puff pastry in the fridge until step 6.

    #SpoonTip: For optimum puffage (yes, that’s a technical term), keep the puff pastry as cool as possible prior to baking.

  • Step 2

    Grate the Gruyère cheese if you haven’t bought it shredded.

    spaghetti, pasta, cheese, vegetable, macaroni, sauce
    Alex Vu
  • Step 3

    Over medium-low heat, add 1 tablespoon of butter, 1 tablespoon of olive oil, the sliced onions, and one clove of garlic to a pan. Season with a pinch of salt and pepper. This will take roughly 20 minutes to caramelize, so patience is key. Stir constantly.

    vegetable, pasta
    Alex Vu
  • Step 4

    Do this next step in three batches to ensure that your mushrooms brown rather than just sweat. Add mushrooms to a pan with 2/3 tablespoon butter and a little olive oil. Season with salt and pepper and a dash of thyme. Use up the last clove of garlic during this step as well.

    saute, mushroom, meat, vegetable
    Alex Vu
  • Step 5

    Check back on your onions to see where they’re at. You are essentially drawing out the onions’ natural sugars without burning them. They should look like this once they’re done.

    sauce, vegetable, seafood, pasta, meat
    Alex Vu
  • Step 6

    Remove the puff pastry dough from the fridge. Using a fork, poke the center area of the dough, leaving a ½ inch border around.

    #SpoonTip: The process of puncturing the dough is called docking. Something to keep in mind when you want to sound professional and impress your friends.

  • Step 7

    Sprinkle the cheese over the puff pastry dough as a base. Next, layer on the mushrooms and add the caramelized onions over top. Be sure to divide it up evenly over the two puff pastry sheets.

    Alex Vu
  • Step 8

    Bake for approximately 20 minutes or until golden brown.

  • Step 9

    Remove from the oven and drizzle a little balsamic vinegar over top. Shave Parmesan cheese over as well for an extra hit of salt and umami.

    pizza, cheese
    Alex Vu
  • Step 10

    Wait for it to cool in order to cut into it and serve.

    pizza, cheese
    Alex Vu