¾ lb(340 g)rutabaga, or other root vegetable such as celeriac or turnip
4 tbsp(56 g)butter, softened
1 tsp(6 g)kosher salt, plus extra
2 - 4 tbsp(30 to 60 ml)heavy cream
Pie Filling
2 tbsp(30 ml)olive oil
1 onion, diced
3stalkscelery, diced
2 carrots, diced
½ lb (227 g)mushrooms, sliced
3garlic cloves, minced
1 tbsp(15ml)chopped fresh thyme, or 1 tsp dried
1 tbsp(15 ml)tomato paste
1 tbsp(15 ml)Worcestershire sauce
1 tsp(6 g)kosher salt, plus extra
½ tsp(3 g)pepper
1 tbsp(8 g)all-purpose flour
1 cup(250 ml)vegetable broth
1 can(540 ml)canned lentils, drained
¼ cup(60 ml)chopped fresh parsley
extra chopped fresh parsley, for garnish
Instructions
Peel and cube both the potatoes and rutabaga. Divide into separate saucepans and cover with water. Season both with a generous pinch of kosher salt. Bring them both to a boil and cook until fork tender. The rutabaga will take about 5 to 10 minutes longer than the potatoes to cook. Drain and keep warm.
Use a potato masher to roughly mash both the rutabaga and potatoes until almost smooth. Add the rutabaga to the potatoes along with the butter, kosher salt, and pepper and mash until smooth. Add 2 tbsp of the heavy cream and mash together. Check the consistency – if it's still too dry, add the remaining cream. Keep warm.
Preheat the oven to 425°F. Place a wide skillet or shallow braiser over medium heat. Add the olive oil along with the onions. Season with a bit of kosher salt. Sauté for 2 to 3 minutes until the onions begin to soften. Add the carrots and celery and turn the heat to low. Sauté for 5 to 7 minutes, stirring regularly, until the vegetables soften.
Add the mushrooms and cook for another 4 to 5 minutes until tender. When the vegetables are all tender, add the minced garlic and chopped fresh thyme. Sauté for another minute until fragrant. Add the tomato paste, Worcestershire sauce, kosher salt and pepper, and cook briefly.
Stir the flour into the vegetables until fully combined before slowly adding the vegetable broth. Bring the mixture to a boil and cook until thickened. Add the lentils and cook for another 2 to 3 minutes to allow the flavours to blend together. Stir in the parsley.
Transfer the filling to a shallow casserole dish or leave in the braiser. Spoon the mashed root vegetable topping evenly over the filling. Bake for 15 to 20 minutes until the filling is bubbling and the top is lightly browned. Top with a bit more chopped parsley for garnish and enjoy!