Preheat the oven to 375°F (190°C).

In a large skillet, heat 1 tablespoon of olive oil over medium heat. Add the chopped onion and garlic, sautéing until the onion is translucent, about 3-4 minutes.

Add the chopped spinach to the skillet and cook until wilted, about 2-3 minutes. Remove from heat and let cool slightly.

In a mixing bowl, combine the ricotta cheese, feta cheese, egg, dill, salt, and pepper. Stir in the cooled spinach mixture until well combined.

Lay one sheet of phyllo dough on a clean surface and brush it lightly with melted butter. Layer another sheet on top and brush with butter again. Repeat this process for 4-5 sheets.

Spoon a portion of the spinach and cheese mixture along one edge of the phyllo dough, leaving about 1 inch of space from the edges. Fold the sides over the filling and roll the dough tightly to form a log. Place seam-side down on a baking sheet.

Repeat steps 5-6 with the remaining phyllo dough and filling, arranging the rolls on the baking sheet.

Brush the tops of the rolls with any remaining melted butter. Bake in the preheated oven for 25-30 minutes or until golden brown and crispy.

Allow to cool for a few minutes before slicing and serving.