Certain foods have traditional been paired together such as mac and cheese, peanut butter and jelly, and peaches and cream. But rarely does such a pairing become both a national dish and favorite dinner of hungry chefs.
Meet Belgium’s beloved moules frites or steamed mussels and savory potato fries. And while that description may seem simple, the dish when properly prepared is legendary.
Fried potatoes were first mentioned in a 1781 Flemish manuscript when potatoes were cut into the shape of small fish and fried when, during the winter, no fresh fish were available.
Mussels were another common Belgian food staple at the time. Because they were cheap and plentiful, mussels, like the potato, were then considered food suitable only for the poor.
Centuries later as World War I raged, American volunteer soldiers enjoyed both mussels and fried when they were on leave from the mud-filled hell of the front line combat trenches. But having never been outside the United States before, they believed they were in France, instead of Belgium, and so christened the cooked potatoes “French Fried”.
Today the popularity of moules frites has not lessened. The combination is served in two separate dishes to insure the crispness of the salty hallmark potatoes. Most restaurants offer a long list of options: Moules Natures (simply steamed with aromatics like celery and leeks, plus a knob of butter), Moules a la Creme (steamed in white wine, enriched with cream), A l'ail (with sliced and minced garlic), and Au Vin Blanc (with white wine).
Dozens of side dip sauces are served with the fries, flavored with everything from fresh herbs to ketchup, but the mayonnaise condiment served is always plain. The freshness of the mussels and the choice of the right kind of potatoes are key to making any moules frites successful.
- 1 tsp. Dijon mustard
- 1 egg yolk
- 1 cup canola oil, plus more for frying
- 2 tsp. white wine vinegar
- 2 tsp. fresh lemon juice
- 1/2 tsp. kosher salt, plus more to taste
- Freshly ground black pepper, to taste
- 2 lb. Yukon Gold potatoes, peeled and cut into 1/4"-thick sticks
- 2 1/2 lb. Taylor mussels, debearded and scrubbed
- 2/3 cup dry white wine
- 2 tbsp. unsalted butter, cubed
- 3 ribs celery, finely chopped
- 1 1/2 leeks, light green and white parts, cut into 1⁄4"-thick slices
- 1/2 large yellow onion, finely chopped
- To make the mayonnaise: Whisk mustard and egg yolk in a large bowl.
- Whisking constantly, slowly drizzle in oil in a thin stream until it begins to emulsify.
- Whisk in vinegar, lemon juice, salt, and pepper.
- Set aside.
- To make the fries: Pour oil into a 6-qt. Dutch oven to a depth of 2" and heat over medium-high heat until a deep-fry thermometer reads 375°.
- Add potatoes and cook until tender, about 8 minutes.
- Using a slotted spoon, transfer fries to a rack set over a rimmed baking sheet and chill.
- Increase oil temperature to 385°.
- Working in batches, add chilled potatoes and cook until golden brown and crisp, about 4 minutes.
- Using a slotted spoon, return fries to rack; season with salt.
- To make the mussels: Heat a 12" high-sided skillet over high heat.
- Add mussels, wine, butter, celery, leeks, and onions; season with salt and pepper, and cover skillet. Cook, occasionally shaking skillet, until all mussels are opened, about 5 minutes.
- Divide mussels between 2 large bowls.
- Serve with fries and mayonnaise.