Wash spinach thoroughly, removing tough stems and wilted leaves.
Place in large pan.
Cover tightly and cook, shaking the pan several times, for about 8 minutes or until tender.
Drain if necessary, chop finely; add pepper and salt and butter.
Place in casserole or deep heatproof dish.
Top spinach with sliced eggs and then with tuna fillets.
Add cheese to the sauce and pour over the tuna.
Sprinkle with breadcrumbs and dot with butter.
Bake in moderately hot oven (400°F - Gas Mark 5) for about 20 minutes.
Garnish with chopped parsley and paprika.