Onion, celery and cheese tart

I absolutely love tarts. The crisp, flaky pastry combined with the soft, warm cheesy filling make a perfect party in the mouth. The caramelized onions and celery add a nice depth of flavor and the cheese adds richness. I have used a mix of sharp cheddar and Monterey Jack cheeses. Goat's cheese also pairs beautifully with the onions. My secret ingredient in this tart is a spoonful of Dijon mustard in the egg custard which takes it to the next level. Try this out and let me know how you like it in the comments.

Serves 6 | Prep. time: 15 minutes | Hands on cooking time: 15 minutes | Baking time: 35 minutes

Ingredients:

• One blind baked* 9" tart shell (use store bought or find recipe here)

• 1 large white onion, thinly sliced

• 3 sticks of celery, finely chopped

• 2 tbsp. olive oil

• salt

• crushed black pepper

• 1/2 tsp thyme

• 1/2 tsp crushed red pepper or chili flakes

• 4 eggs

• 1/4 cup milk

• 1/2 tbsp. Dijon mustard

• 1/4 cup sharp Cheddar + Monterey Jack cheese

Directions:

1. Pre-heat oven to 350F.

2. In a frying pan, heat the olive oil on medium heat and add the onions and celery. Add a pinch of salt and and let the vegetables cook for about 10 minutes, until caramelized. Stir intermittently.

3. Once vegetables are caramelized, add the thyme, crushed red pepper and season with salt and black pepper as needed. Turn off the heat and set vegetables aside to cool.

4. Prepare the egg custard by beating together the eggs, milk and Dijon mustard. Add 1/4 tsp. salt and 1/4 tsp. crushed black pepper and set aside.

5. To assemble the tart: To the blind baked tart shell, add a layer of cheese (use only half the cheese here), then add the caramelized vegetables and spread evenly. Pour the egg custard mixture evenly over the vegetables. Sprinkle the rest of the cheese over the top and bake tart at 350F for 35 minutes.

6. Let tart rest at room temperature for 10 minutes before slicing and serving.

* Blind baking a tart shell is the process of baking a tart or pie crust without any filling. A blind baked crust is required when the tart is filled with an unbaked filling. The blind baked crust offers support and structure to the filling and prevents the bottom of tart from getting soggy.