Side Dish: Canada – Prince Edward Island – PEI Seaweed Pie

Serving Size: 6

Approximate Time

Prep 50 min

Cook 50 min

Additional 45 min

Total 1 hr 55 min

Ingredients

- For the pastry:
- 2 1/2 cups (312 g) all-purpose flour
- 1 tsp (6 g) fine salt
- 1 cup (226 g) cold unsalted butter, cubed
- 6–8 tbsp (90–120 ml) ice water

- For the filling:
- 1.5 lb (680 g) Yukon Gold or russet potatoes, peeled and cut into 1–2 in (2.5–5 cm) chunks
- 4 oz (115 g) cleaned fresh Irish moss (Chondrus crispus), chopped (or 0.5 oz / 14 g dried, rehydrated)
- 1 medium (about 6 oz / 170 g) yellow onion, finely diced
- 2 tbsp (30 g) unsalted butter
- 1/3 cup (80 ml) whole milk (or cream for richer filling)
- 2 tbsp (30 g) grated sharp cheddar (optional)
- 1 tbsp (8 g) all-purpose flour (to bind)
- 1 tsp (5 ml) lemon juice
- 1 tsp (6 g) sea salt, plus more to taste
- 1/2 tsp (1 g) freshly ground black pepper
- 2 tbsp (8 g) chopped fresh parsley
- 1 large egg, beaten (for egg wash)

Instructions

Short Description:
A rustic savory pie combining mashed potatoes, sautéed onions and locally harvested Irish moss (seaweed) baked in a flaky double crust — a distinctive Prince Edward Island side to serve alongside fish or roast meats.

Regional Notes:
This Prince Edward Island version uses Irish moss (Chondrus crispus) harvested from PEI shores, folded into a potato-and-onion filling; the seaweed gives a briny, slightly mineral note that distinguishes it from generic potato pies elsewhere. Preparation emphasizes careful cleaning and brief blanching of the moss to preserve its texture and regional flavor.

1. Prepare the Irish moss: If using fresh, rinse thoroughly under cold water to remove sand and grit, then soak in cold water for 10 minutes, changing water if needed. For dried moss, rehydrate in warm water for 10–15 minutes then rinse. Trim any tough bits and chop coarsely. Blanch the cleaned moss in boiling water for 30–60 seconds, then drain and plunge into ice water; drain well and squeeze gently to remove excess water. Set aside.
2. Cook the potatoes: Place potato chunks in a pot, cover with cold water, add a pinch of salt, and bring to a boil. Simmer until tender, about 12–15 minutes. Drain well and return to the pot.
3. Make mashed potato base: Add 1 tbsp (15 g) butter and 1/3 cup (80 ml) milk to the drained potatoes and mash until smooth but still slightly textured. Stir in 1 tsp (5 ml) lemon juice, 1 tsp (6 g) sea salt, and 1/2 tsp (1 g) black pepper. Set aside to cool slightly.
4. Sauté onion and combine with moss: In a skillet over medium heat, melt 1 tbsp (15 g) butter. Add the diced onion and cook until translucent and starting to brown, about 6–8 minutes. Add the blanched Irish moss and sauté 1–2 minutes to warm through. Sprinkle in 1 tbsp (8 g) flour and cook 1 minute more to remove raw flour taste; remove from heat and let cool slightly.
5. Finish the filling: Fold the onion–moss mixture into the mashed potatoes. Stir in grated cheddar (if using) and chopped parsley. Taste and adjust seasoning with additional salt and pepper as needed. The filling should be moist but not runny.
6. Make the pastry: In a large bowl, whisk together 2 1/2 cups (312 g) flour and 1 tsp (6 g) salt. Cut in the cold cubed butter with a pastry cutter or fingertips until mixture resembles coarse crumbs with some pea-sized pieces. Sprinkle ice water, 1 tbsp at a time, and gently mix until dough just comes together. Divide into two disks, wrap in plastic, and chill for 20–30 minutes.
7. Assemble the pie: Preheat oven to 400°F (200°C). Roll out one dough disk on a lightly floured surface to fit a 9-inch (23 cm) pie dish with slight overhang. Line the dish with the bottom crust. Fill with the potato–seaweed mixture, mounding slightly. Roll out the second disk and place over the filling; trim excess and crimp edges to seal. Cut a few vents in the top crust to release steam.
8. Egg wash and bake: Brush the top crust with the beaten egg. Place the pie on a baking sheet to catch drips and bake at 400°F (200°C) for 35–45 minutes, until the crust is golden brown and the filling is heated through.
9. Rest and serve: Let the pie rest 10–15 minutes before slicing. Serve warm as a side to grilled or baked fish, roast meats, or a seafood chowder.