Preheat the oven to 400°F.

Cook fresh spinach over medium high heat in a large dry non-stick skillet with a pinch of salt until completely wilted, about 4 minutes.

Remove spinach with a slotted spoon, leaving the liquid in the skillet.

Set spinach aside.

Pour liquid from the skillet into a small bowl and set aside.

Wipe skillet dry.

Melt butter in the skillet over medium heat.

Add flour and cook, stirring, until blended but not brown, about 1 minute.

Add onion and cook until soft but not brown, about 3 minutes.

Add reserved spinach liquid and heavy cream very slowly, stirring constantly, to avoid lumps.

Cook until smooth and thick, about 30 seconds.

Add salt, pepper, celery seeds, garlic, cayenne pepper and cheese.

Stir until melted, about 2 to 3 minutes.

Add spinach back to skillet and stir to completely blend.

Spoon the spinach into a serving dish.

Combine bread crumbs with olive oil and sprinkle over the spinach. Serve immediately, or bake for 15 minutes, or until bread crumbs are crispy and golden and spinach is hot and bubbly.