I had some squash filling left over after making the ravioli the other day, so the Kidlet and I decided to turn it into a quiche. I seasoned the custard with salt, pepper, and lemon thyme and then added some extra kale and a layer of balsamic caramelized onions on top of the squash. I finished it off with a little grated Cheddar. I'm pretty happy with how it came out, but I do regret not adding a few sautéed onions. I think it would've been nice to have the mushrooms in there to give a distinct textural element in addition to a bit of extra umami. Next time...

Squash & Caramelized Onion Quiche

Adapted from King Arthur Flour

Ingredients

Crust

• ~200g shortcrust pastry
• 4 large egg whites

Custard

• 3 large eggs
• 1 c. milk
• 1/2 tsp. fresh lemon thyme
• 1/2 tsp. black peppercorns, ground
• 1/4 tsp. coarse sea salt, ground

Filling

• 227g cremini mushrooms, sliced
• 2 Tbsp. water
• 2 Tbsp. olive oil, divided
• 1 c. Squash ravioli filling
• 2 onions, halved and sliced
• 1 Tbsp. balsamic vinegar
• 1/2 c. chopped kale
• 1/2 c. shredded Cheddar cheese

Directions

Crust

1. Roll out the pastry and place it in a 23cm (9") pie plate.
2. Line with parchment paper and fill with pie weights, beans, rice, or sugar.
3. Bake at 200°C (400°F) for 15-20 minutes.
4. Remove parchment paper and pie weights, prick crust with fork and brush with some of the egg whites. Reserve the remaining egg whites for the custard.
5. Return to oven and bake for another 5-8 minutes.
6. Remove from oven and set aside.

Custard

1. Whisk eggs with egg whites and milk.
2. Mix in thyme, salt, and pepper. Set aside.

Filling

1. Cook mushrooms with water over medium heat. Cover and continue cooking until mushrooms soften.
2. Uncover, add 1 Tbsp. of oil, and season with salt and pepper if desired. Continue cooking until desired done-ness. Set aside.
3. Heat remaining 1 Tbsp. of oil over medium-low heat.
4. Add onion and cook, stirring occasionally, for at least 20 minutes.
5. Add balsamic vinegar and cook for another minute or two.

Assembly

1. Place squash mixture in bottom of pie shell. Do not press or pack it in, there should be room for custard to flow between the pieces of filling.
2. Layer mushrooms over squash.
3. Layer the kale over the mushrooms.
4. Layer the onion over the kale.
5. Pour the custard into the pie shell. You may not need it all. Do not overfill!
6. Sprinkle cheese on top.
7. Bake at 190°C (375°F) for 35-45 minutes.