Steamed Pei Mussels & Frites Recipe

Prepare potatoes

Cut peeled russet potatoes into 1/3-inch to 1/2-inch sticks for classic frites. Rinse fries under cold water until water runs clear to remove excess starch. Soak the cut potatoes in a bowl of cold water for at least 30 minutes, up to 2 hours, refrigerated.

Par-dry and coat

Drain potatoes and pat thoroughly dry with clean kitchen towels or paper towels. Toss the dried sticks with 1 tablespoon cornstarch until lightly coated; this helps create a crisp exterior. Season lightly with 1/2 teaspoon salt and 1/8 teaspoon black pepper (the remainder of salt will be adjusted after frying).

Heat oil

Pour 3 to 4 cups vegetable oil into a heavy-bottomed pot or deep fryer to a depth of about 2 to 3 inches. Heat oil to 325°F (163°C) for the first, blanching fry. If you don't have a thermometer, the oil should shimmer but not smoke.

First fry (blanch)

Fry batches of potatoes (do not overcrowd) for 3 to 4 minutes until they are softened but not browned. Use a slotted spoon to transfer blanched fries to a wire rack or paper towels to drain. Let fries rest for at least 10 minutes; they can cool while you prepare mussels.

Second fry (crisp)

Increase oil temperature to 375°F (190°C). Fry the blanched fries in batches for 2 to 3 minutes, or until golden brown and crisp. Remove to a rack or paper towels, immediately season with the remaining 1/2 teaspoon salt (or to taste), sprinkle optional Parmesan and smoked paprika if using. Keep warm in a low oven (200°F / 95°C) while finishing mussels.

Make quick aioli

In a small bowl whisk together 1 egg yolk, 1 teaspoon lemon juice, 1/2 teaspoon Dijon mustard and minced garlic. Very slowly drizzle in neutral oil while whisking vigorously (or use an immersion blender) until mixture thickens into an emulsion. Stir in 1 teaspoon olive oil, season with 1/4 teaspoon salt and 1/4 teaspoon pepper. Taste and adjust acidity or salt. Refrigerate until serving. (If you prefer a safer version, use pasteurized egg yolk or substitute 3 tablespoons mayonnaise.)

Clean and check mussels

Rinse mussels under cold running water, discard any with cracked shells or that remain open when tapped. Remove beards by pulling toward the hinge. Keep mussels cold until ready to cook.

Sauté aromatics

In a large wide pot or Dutch oven, heat 1 tablespoon olive oil and 2 tablespoons unsalted butter over medium heat until butter foams. Add 2 tablespoons minced shallot and sauté 2 to 3 minutes until translucent but not browned. Add 3 minced garlic cloves and 1 teaspoon thyme leaves; cook 30 seconds until fragrant.

Deglaze and steam

Pour in 1 cup dry white wine and 1 cup stock, increase heat to high and bring to a vigorous simmer. Scrape any browned bits from the bottom. Add the cleaned mussels to the pot, cover with a tight-fitting lid and steam for 4 to 6 minutes, shaking the pot once or twice, until mussels have opened. Discard any mussels that remain closed after 6 minutes.

Finish sauce

Remove pot from heat and transfer opened mussels into a warmed serving bowl with a slotted spoon, leaving cooking liquid. Reduce the cooking liquid over medium-high heat for 2 to 3 minutes if it seems thin. Stir in remaining 1 tablespoon butter, the zest and juice of 1 lemon, and 1 tablespoon chopped parsley. Taste and adjust seasoning with 1/2 teaspoon salt and 1/4 teaspoon freshly ground black pepper as needed.

Serve

Pour finished broth over the mussels in the serving bowl, garnish with additional parsley and an extra lemon wedge. Serve immediately with hot frites and aioli or crusty bread to soak up the sauce.