01 -
Place the frozen white bread loaf in a greased bowl and cover with plastic wrap. Allow it to thaw and double in size in a warm environment, approximately 2 to 3 hours.
02 -
Dice the green bell pepper and yellow onion evenly, and thinly slice the mushrooms. Heat 1 tablespoon of butter in a skillet over medium heat and sauté the vegetables until tender and lightly browned, about 6 minutes. Remove from heat and let cool slightly.
03 -
Set the oven to 375 degrees Fahrenheit (190°C). Line a baking sheet with parchment paper or lightly grease it to ensure easy removal.
04 -
On a floured surface, roll the risen dough into a rectangle approximately 12 by 18 inches (30 by 45 cm), ensuring even thickness without tearing.
05 -
In a small bowl, combine mayonnaise and garlic powder. Mix thoroughly and spread evenly over the dough, leaving a 0.5-inch (1.25 cm) border around the edges.
06 -
Evenly arrange the roast beef slices over the garlic mayo. Distribute the sautéed vegetables atop the meat, then layer provolone slices over the vegetables, overlapping as needed.
07 -
Starting from a long edge, roll the dough like a jelly roll, keeping it tight and tucking in fillings to prevent spilling. Pinch the seams and ends firmly to seal.
08 -
Place the stromboli, seam side down, on the prepared baking sheet. Brush the top with melted butter and sprinkle garlic salt, sesame seeds, and dried parsley evenly.
09 -
Bake for 15 to 20 minutes or until the crust is golden brown and the internal temperature reaches 165 degrees Fahrenheit (74°C).
10 -
Remove from oven and let rest for 5 minutes to firm up. Slice using a serrated knife and serve warm.