Caramelized Onion and Mushroom Tart

This caramelized onion and mushroom tart was delicious all on its own. Then I decided to add on the balsamic arugula after it was baked and it went from yum to wow!

Lets start off with the phyllo pastry. I don’t often buy it, I’m not sure why. But I decided after visiting Whistler and having a delicious pastry, that I wanted to recreate it. That was months ago, and I never did that. It was clear that I needed to use this phyllo pastry dough and make something tasty. It also worked out that I just bought a 10lb bag of red onions. I feel like the stars were aligning and this delicious caramelized onion and mushroom tart was meant to happen!

I started off with the onions. Grabbing out my large cast iron frying pan, I drizzled some avocado oil in, and tossed in two large sliced onions. As those were frying up, I chopped up a bunch of mushrooms to add on as well. Then comes the garlic. There always has to be garlic on a tart, flatbread, pizza, pretty much everything. If you’d like this to be vegan, either leave off the feta cheese or use a vegan cheese. There are so many delicious options out there today.

This tasty tart was looking mighty fine in the oven. Once it came out, I decided that it needed some green. It just happens that I always seem to have arugula in my fridge. I grabbed out my balsamic vinegar from the pantry, and drizzled it on the arugula. After coating the lovely peppery greens, I added them to the top. This took it to the next level. Now it’s time for you to go ahead and make this tasty dish. It’s perfect for a dinner alongside a salad and it’s also the perfect appetizer!

For other delicious dinner ideas, click here!

onion and mushroom tart
tart appetizer
savoury phyllo tart

Caramelized Onion and Mushroom Tart

A delicious flaky appetizer.
Prep Time15 mins
Cook Time45 mins
Total Time1 hr
Course: Appetizer, Main Course, Side Dish
Cuisine: Mediterranean
Servings: 6 people


  • Large baking sheet


  • 10 sheets phyllo pastry dough
  • 2 large red onions, sliced
  • 2 cloves garlic, pressed
  • 1 cup crumbled feta cheese
  • 1/4 cup avocado oil divided
  • 2 cups arugula
  • 2 tbsp` balsamic vinegar


  • Preheat your oven to 375°.
  • In a large frying pan, add 1 tbsp of the oil and all of the onion. Cook over medium heat stirring often until the onions are caramelized. This should take 10-15 minutes. Add in the mushrooms and saute until they release their water. Add in the garlic and cook for an additional minute.
  • While the onions are cooking, brush a baking sheet with oil. Start layering the phyllo pastry. Brush each layer with oil before layering the next piece. Once you have layered all 10 pieces, fold over the edges as best as possible to create a crust. Brush with oil.
  • When the onions and mushrooms are done, layer evenly over the phyllo pastry. You don't need to leave much of an edge. Sprinkle the feta cheese evenly over the mushrooms and onions.
  • Bake in he preheated over for about 30 minutes or until golden brown.
  • While the tart bakes, toss the arugula in the balsamic vinegar.
  • Once the tart is out of the oven and has cooled for a few minutes, sprinkle the arugula on top. Slice the tart into squares and serve immeditely.

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