Mix the sourdough starter, water, flour, salt, and oil in a medium bowl until a shaggy dough forms, then knead it on the counter for 3 to 5 minutes. The dough should become smooth, elastic, and only lightly tacky by the end.

Cover the dough and leave it at room temperature for 4 to 8 hours, or refrigerate it overnight for a slower fermentation. It is ready when it looks puffier and feels airy rather than dense.

Portion the fermented dough into pieces about the size of ping pong balls, shape them into smooth balls, and let them rest for 15 minutes. This short rest relaxes the dough so it rolls out without springing back.

Roll each ball on a lightly floured surface into a 3 to 4 inch circle about 1/4 inch thick. Keep them at that thickness so they stay chewy and do not turn hard when cold.

Warm a cast iron skillet over medium heat, then cook one flatbread at a time for 1 to 2 minutes on the first side and about 1 minute after flipping. Flip when small bubbles puff across the top, the bottom shows pale golden spots, and the dough smells lightly toasted.

Transfer the cooked flatbreads to a rack and let them cool completely before stacking or packing. If any warmth is trapped, steam will soften the crust.

Place the crushed tomatoes, olive oil, garlic, salt, dried oregano, and Italian seasoning in a medium bowl. The mixture will look loose at first but should stay thick enough to spoon neatly.

Whisk until the sauce is evenly blended. You should see the seasonings distributed throughout with no oily streaks left on top.

Set out six containers large enough to hold separate pizza kit components. A snug layout helps keep everything from sliding around.

Place three flatbreads in one corner of each container and stack 9 pepperonis in another corner. The crusts should be fully cool and flexible at this stage.

Spoon 3 tbsp of marinara into a small lidded jar or container that fits inside the lunch box, then close it tightly. The sauce container should stay upright and secure without wobbling.

Add 1/4 cup of cheese in a small baggie or a parchment sling and tuck it into the box beside the other components. Keeping the cheese separate helps it stay dry and loose instead of clumping.

Add a spoon and pack the lunchable with an ice pack to keep the ingredients cold. The finished box should feel organized, compact, and ready to assemble at lunch.