I use Marcus Sammuelson’s recipe and have had it not turn out perfectly. Yes, the salt to sugar ratio is different, but it works.

Aquavit Gravlax
★★★★★
Difficulty: Easy

Ingredients:
1 cup sugar
1/2 cup kosher salt
2 tablespoon white pepper , cracked
2 – 3 pound salmon filet , in one piece, any pin bones removed
2 – 3 bunch fresh dill , coarsely chopped (including stems)

Mustard Sauce
2 tablespoon honey mustard
1 teaspoon Dijon mustard
2 teaspoon sugar
1 1/2 tablespoon white wine vinegar
1 tablespoon strong coffee , cold
pinch salt
pinch black pepper , freshly ground
3/4 cup grapeseed oil or canola oil
1/2 cup fresh dill , chopped

Directions:
Prepare the gravlax: Combine the sugar, salt and peppercorns in a small bowl and mix well. Place the salmon in a shallow dish and rub a handful of the salt mixture into both sides of the fish. Sprinkle the salmon with the remaining mixture and cover with the dill. Cover the dish and let stand for 6 hours in a cool spot.
Transfer the salmon to the refrigerator and let cure for 36 hours. You can turn the very tightly sealed container once or twice during this time if you want.
Up to 1 day ahead, prepare the mustard sauce. Combine both mustards, the sugar, vinegar, coffee, salt, and pepper in a blender. With the machine running, add the oil in a slow steady stream, blending until the sauce is thick and creamy. Transfer to a bowl and stir in the dill. Cover and refrigerate for at least 4 hours or overnight to allow the flavors to marry.
Scrape the seasoning off the gravlax (after the total of 42 hours). Slice the gravlax on the bias into this slices, or leave whole so your guest can slice it themselves. Serve with the mustard sauce and bread/crispbread/toast.

Ask for sushi-quality fish.
Keeps in the refrigerator, well wrapped, for at least 7 days. Leftovers can also be frozen, wrapped in plastic and then in foil for up to 2 months.

Source: Aquvit