Unroll the puff pastry sheets and cut each one in half. Meanwhile, steam the spinach and drain it well. Also, make sure the ricotta is well drained. Chop the spinach with a knife and place it in a mixing bowl. Add the ricotta, Parmesan, salt, pepper, and nutmeg. Mix well and set aside.

Once ready (you can prepare this in advance), transfer the mixture to a piping bag. Cut off the tip (no piping tip needed) and pipe the filling along the center of each pastry strip (I filled 3 strips). Seal the edges.

Grease a bundt pan with olive oil and dust with breadcrumbs, shaking out any excess. Join the ends of each filled pastry strip to form a ring.

Place the ring in the pan, sealing the ends and shaping as needed. Brush with egg yolk and bake at 350°F (180°C) for about 30 minutes. Once baked, decorate with cherry tomatoes and rosemary sprigs.