Tuna Spinach Mornay Pie With Potato And Celeriac Mash - cooking recipe

Ingredients

1 lb potatoes, peeled, coarsely chopped
10.5 oz celeriac, peeled, coarsely chopped
2 tbsp milk
2 1/2 tbsp butter
1/4 cup finely grated Parmesan cheese
None None Tuna Spinach Mornay Pie
4 tbsp butter
1 None medium Spanish onion, thinly sliced
1/4 cup all-purpose flour
2 cups milk, warmed
5 oz baby spinach
1 (15 oz) can tuna in springwater, drained
2 tbsp lemon juice

Preparation

To make the potato and celeriac mash, boil, steam or microwave potatoes and celeriac, separately, until tender. Drain then transfer to a large bowl. Mash with milk and butter until smooth. Stir in cheese and cover to keep warm.
Meanwhile, melt butter in a medium saucepan over medium heat. Cook onion, stirring, for 5 mins, or until softened. Add flour and cook, stirring, until mixture thickens and bubbles. Gradually add milk and stir until mixture boils and thickens. Remove from heat and stir in spinach, tuna and lemon juice.
Preheat broiler.
Spoon tuna mixture into a shallow baking dish and top with potato and celeriac mash. Broil until lightly browned. Serve.