My mum's Tuna Mornay recipe - it's really yum!

60g butter
1/3 cup plain flour
2 1/2 cups milk
1 chicken stock cube (or 1tsp chicken stock powder)
1/3 cup grated cheese
425g can chunky tuna (drained)
1/4 tsp cracked black peppercorns
1 cup frozen peas
2 hard boiled eggs (sliced)
Topping:
1 1/2 cups breadcrumbs
30g melted butter
1/3 cup grated cheese.

Melt butter in pan, stir in flour and stir over heat until dry and grainy. Remove from heat, gradually stir in milk and crumbled stock cube. Stir over heat until sauce boils and thickens. Stir in cheese, tuna, peas and peppercorns, gently fold in eggs. Pour into ovenproof dish and sprinkle with topping (just mix all topping ingredients together in a bowl and spread evenly over top of tuna mixture). Bake in moderate oven for 25 mins or until brown.