In a large mixing bowl, combine the all-purpose flour, instant yeast, and salt. Create a well in the center and pour in the olive oil and warm water. Mix until a shaggy dough forms, then knead on a lightly floured surface for about 5–7 minutes until smooth and elastic.

Place the dough in a greased bowl, cover with a damp cloth, and let it rise in a warm spot for about 1 hour or until doubled in size.

While the dough rises, heat a tablespoon of olive oil in a skillet over medium-low heat. Add sliced onions and a pinch of salt, and cook gently for 20–25 minutes until caramelized and golden brown.

Stir in minced garlic and fresh spinach, cooking for an additional 2–3 minutes until spinach is wilted. Remove from heat and let cool slightly.

Once the dough has risen, punch it down and roll it out into a rectangle about 1/4 inch thick. Spread a thin layer of marinara sauce, leave a border on all sides, distribute the filling, and roll tightly.

Cut the rolled dough into 1-inch thick slices and place in a greased baking dish, cover and allow to rise for another 30 minutes.

Preheat the oven to 375°F (190°C). Brush rolls with olive oil if desired, then bake for 20–25 minutes until golden and puffed.

Remove and let cool for 5–10 minutes before serving warm, with extra marinara on the side.