Vegetable Stromboli Recipe

Activate yeast

In a medium bowl, combine warm water and sugar, stir to dissolve. Sprinkle the active dry yeast over the surface and let sit 5–10 minutes until foamy.

In a large mixing bowl (or stand mixer bowl), combine 4 cups of the flour and the salt. Add the yeast mixture and olive oil. Mix until a shaggy dough forms, then add remaining flour 1/2 cup at a time until the dough pulls away from the bowl and is soft but not sticky.

Turn dough onto a lightly floured surface and knead 6–8 minutes (or knead with dough hook on medium 5–6 minutes) until smooth and elastic. Add small pinches of flour as needed to prevent sticking but avoid making dough dry.

Place dough in a lightly oiled bowl, turning once to coat. Cover with plastic wrap or a damp towel and let rise in a warm draft-free place until doubled in size, about 1 to 1¼ hours.

Punch the dough down to release air and let rest 10 minutes before rolling.

While dough is rising, prepare the filling. Heat 2 tablespoons olive oil in a large skillet over medium-high heat.

Add sliced onions and cook 3–4 minutes until beginning to soften. Add green pepper and cook 3 more minutes until peppers soften but still have some bite.

Add mushrooms and cook 5–6 minutes, stirring occasionally, until mushrooms release their moisture and begin to brown.

Add minced garlic, chopped spinach, Italian seasoning, red pepper flakes, salt, and black pepper. Cook 1–2 minutes until spinach wilts and garlic is fragrant. Remove skillet from heat and transfer vegetables to a bowl to cool to room temperature. If mixture is very wet, drain excess liquid by pressing with a spoon or straining briefly so stromboli doesn't become soggy.

Preheat oven to 425°F (220°C). Line a baking sheet with parchment paper or lightly oil a baking sheet.

On a lightly floured surface, roll the rested dough into a rectangle about 12 x 16 inches (or roughly 1/4-inch thick). Try to keep edges slightly thicker to hold filling.

If using ricotta, stir together ricotta and 2 tablespoons Parmesan in a small bowl and spread a thin, even layer (about 1/3 cup) over the dough leaving a 1-inch border on all sides.

Sprinkle half of the shredded mozzarella evenly over the ricotta (or directly on dough if not using ricotta). Spread the cooled vegetable mixture evenly over the cheese, leaving the 1-inch border.

Top the vegetables with the remaining mozzarella and the remaining Parmesan, distributing evenly but leaving the border clear.

Starting from a long edge, carefully roll the dough tightly into a log, tucking the filling in as you go to avoid pockets. Pinch the seam to seal and fold the ends under to enclose filling.

Transfer the stromboli seam-side down to the prepared baking sheet. Beat the egg with 1 teaspoon water and brush the top of the stromboli with the egg wash. Optional: sprinkle sesame seeds or everything seasoning on top. Using a sharp knife, make 3–4 small diagonal slits in the top to allow steam to escape.

Bake in the preheated oven for 20–25 minutes until crust is golden brown and internal temperature reaches about 190°F (88°C). Rotate pan halfway through baking for even browning.

Remove stromboli from oven and let rest 10 minutes before slicing. This helps the filling set and prevents leaking.

Slice into 1–1½ inch thick slices and serve warm with warmed pizza sauce or marinara for dipping.