Tuna, Spinach And Potato Pie - cooking recipe

Ingredients

None None FOR THE POTATO AND CELERIAC MASH
14 oz potatoes, peeled and coarsely chopped
10 oz celeriac, peeled and coarsely chopped
2 tbsp milk
2 tbsp butter
1/4 cup finely grated Parmesan cheese
None None FOR THE FILLING
3 tbsp butter
1 None onion, thinly sliced
1/4 cup flour
5 oz baby spinach leaves
3 cans (5 oz each) tuna in water, drained
2 cups milk, warmed
2 tbsp lemon juice

Preparation

For the potato and celeriac mash, boil, steam or microwave potatoes and celeriac, separately, until tender. Drain. Place in large bowl; mash with milk and butter until smooth. Stir in cheese. Season to taste. Cover to keep warm.
For the filling, melt butter in medium saucepan. Cook onion, stirring, for 5 mins, or until softened. Add flour and cook, stirring, until mixture thickens and bubbles. Gradually add milk; stir until mixture boils and thickens. Remove from heat; stir in spinach, tuna and lemon juice. Season to taste.
Preheat the broiler. Spoon tuna mixture into shallow 1 1/2-quart baking dish. Top with potato and celeriac mash. Broil until lightly browned.