Preheat oven to 350°F (175°C).

Lightly butter a 11 x 7 x 2-inch baking dish.

In a large bowl, combine chopped spring onion, crumbled feta cheese, grated Edam cheese, crumbled Roquefort cheese (optional), chopped fresh dill, fresh breadcrumbs, heavy cream, and eggs.

In a large pot, heat olive oil over medium-high heat.

Add coarsely chopped spinach to the pot and sauté until wilted and juices evaporate, approximately 3 minutes.

Transfer the sautéed spinach to a strainer and drain well to remove excess moisture.

Allow the spinach to cool slightly.

Add the drained spinach to the bowl with the cheese mixture and mix well to combine.

Empty the spinach and cheese mixture into the prepared baking dish.

Bake in the preheated oven until heated through and bubbly, about 30-35 minutes.