In the bowl of your stand mixer (or a large mixing bowl if mixing by hand), whisk together your warm water, yeast, and sugar. Let this sit undisturbed for about 5 minutes. You'll notice it become foamy and smell wonderfully yeasty—that's exactly what you want. This step ensures your yeast is alive and ready to work.

Add the olive oil, salt, and flour to your yeast mixture. If using a stand mixer, beat on low speed for about 2 minutes until everything comes together into a shaggy dough. If mixing by hand, stir vigorously with a wooden spoon or silicone spatula until combined. Don't worry if it looks rough—that's normal at this stage.

Switch to the dough hook on your mixer (if using one) and beat for a full 5 minutes. If kneading by hand on a lightly floured surface, work the dough for 5 full minutes with consistent pressure. The dough will transform from sticky to smooth and elastic. If it becomes too sticky during kneading, sprinkle just 1 teaspoon of flour at a time—don't overdo it. Your final dough should feel soft and slightly tacky, not dry. To test if you've kneaded enough, poke your dough with your finger. It should slowly bounce back. For extra confidence, do the windowpane test: tear off a small piece and gently stretch it thin. Hold it to the light. Does light pass through without tearing? You're done. If not, keep kneading for another minute or two.

Place your dough in a lightly oiled bowl, turning it once to coat all sides. Cover with a clean kitchen towel or plastic wrap. Let it rise at room temperature for 1 to 1.5 hours until it's roughly doubled in size. You'll know it's ready when you gently poke it and the indentation stays rather than bouncing back.

While the dough rises, prepare everything for filling. Layer your sliced Italian meats on a plate. Shred your cheese if you haven't already (freshly shredded really does melt better than pre-packaged). Mix together the melted butter, minced garlic, fresh parsley, and red pepper flakes in a small bowl. This garlicky butter will brush on top and create that irresistible crust.

Turn your risen dough onto a lightly floured surface. Using your hands or a rolling pin, gently stretch and shape it into a rectangle approximately 14 by 10 inches. Don't stress about perfect dimensions—close is plenty good enough. Leave about a 1-inch border on all sides bare (you'll fold these edges later).

Starting about an inch from one of the long edges, layer your fillings in this order: meats first, then cheese. Don't overstuff—think generous but not excessive. Leave that 1-inch border on all sides so nothing leaks out during baking. The meats should cover most of the surface, followed by an even layer of cheese.

Starting from the long edge closest to your fillings, roll the dough tightly toward the opposite edge, using gentle but firm pressure. You're creating a log, not a burrito—consistent tension matters. Once fully rolled, pinch the seam and both short ends closed so nothing escapes during baking. Place seam-side down on a parchment-lined baking sheet.

Beat together one large egg with 1 tablespoon water. Brush this mixture all over your stromboli. This creates that beautiful golden-brown exterior everyone loves. Now brush your prepared garlic butter mixture over the egg wash. Sprinkle generously with flaky sea salt, dried parsley, and Parmesan if using.

Preheat your oven to 375°F. Bake for 20 to 25 minutes until the exterior is deep golden brown and the cheese is visibly melted inside (you might see it peeking through small cracks). The aroma in your kitchen will be absolutely incredible. Let it cool for 3 to 5 minutes before slicing—this allows the cheese to set slightly so it doesn't pour out everywhere.