Veggie Stromboli

Bahan-bahan (8 porsi)

• 16 ounce refrigerated or homemade pizza dough
• 1 1/2 tbsp olive oil (extra virgin)
• 3/4 tsp kosher salt
• 8 ounces thinly sliced cremini mushrooms (stems trimmed)
• 1 medium red onion (chopped)
• 3 cups baby spinach
• 3 cloves garlic (crushed)
• 1 cup part-skim shredded mozzarella cheese
• 1 egg white (beaten)
• sesame seeds (optional for topping)
• marinara sauce (for serving)