In a mixing bowl, combine the flour, yeast, and salt. Make a well, add oil and warm water, mixing until shaggy dough forms.

Knead the dough for 5-7 minutes until smooth and elastic. Place in a greased bowl, cover, and let rise for 1 hour.

In a skillet, heat olive oil, add sliced onions and salt. Sauté for 20-25 minutes until caramelized.

Add minced garlic and spinach, cook for 2-3 minutes until spinach wilts. Allow filling to cool.

Punch down risen dough, roll out to ¼ inch thick. Spread marinara sauce, add cooled filling, and roll tightly.

Slice rolls into 1-inch pieces, place in a greased baking dish, cover with a towel, and let proof for 30 minutes.

Preheat oven to 375°F (190°C). Brush tops with olive oil if desired. Bake for 20-25 minutes until golden brown.

Let cool for 5-10 minutes. Serve warm with marinara for dipping.