In a mixing bowl, combine all-purpose flour, 00 flour, yeast, and salt. Gradually add lukewarm water and olive oil until a shaggy dough forms. Knead for about 10 minutes until smooth.

Let the dough rise for 4-8 hours in a greased bowl covered with a damp cloth.

Heat a skillet over medium heat, add olive oil, and sauté diced red onions, mushrooms, and bell peppers for 5-7 minutes. Set aside to cool.

In the same skillet, sauté minced garlic with leftover onions, then stir in the tomato sauce. Simmer for 10-15 minutes until thickened.

Preheat oven to 450°F (230°C). Roll out the dough, spread sauce on half, add fillings, fold over, and seal edges.

Place calzones on a parchment-lined baking sheet, brush with an egg wash, and bake for 20-25 minutes until golden brown.