Step 1.

Preheat oven to 425°F.

Step 2.

Cook pasta according to packaging instructions until al dente. Drain and set aside.

Step 3.

In a large pot over high heat, add the olive oil and onions. Sauté for 2-3 minutes until translucent.

Step 4.

Add in carrots and celery, sauté for another 2-3 minutes.

Step 5.

Add mushrooms and sauté for another 2-3 minutes until mushrooms soften.

Step 6.

Add the garlic and sauté for 1 minute.

Step 7.

Add the red wine to deglaze and scrape up brown bits from the bottom of the pan. Cook for 2 minutes until wine reduces.

Step 8.

Add crushed tomatoes, kosher salt and black pepper to pot and stir to combine.

Step 9.

Bring to a simmer and let simmer for 5-10 minutes. Remove from heat and cool for 10-15 minutes stirring every few minutes to let steam out.

Step 10.

In a small bowl, combine eggs and whole milk. Set aside.

Step 11.

In a large bowl, combine cooked spaghetti, veggie Bolognese, egg mixture, 1 cup of fontina cheese, 1 cup of mozzarella and sliced pepperoni if using.

Step 12.

Grease the inside of a 9-inch springform pan with butter and tightly wrap the outside in aluminum foil to seal.

Step 13.

Pour the pasta mixture into springform pan and press the spaghetti mixture down slightly.

Step 14.

Place pie into oven for 25 minutes.

Step 15.

Remove from oven and top with remaining cheese.

Step 16.

Place back in oven for an additional 10 minutes until cheese has melted and begins to brown.

Step 17.

Remove from oven and run a knife around the edges of the pan. Let rest for 10-15 minutes for spaghetti to set.

Step 18.

Remove aluminum foil and springform pan.

Step 19.

Cut into 12 slices.