In saucepan, combine rutabaga with enough water to cover. Bring to a boil. Boil, covered, for 25 to 30 minutes, or until rutabaga is very soft. Drain and transfer to food processor. Pulse until very smooth and creamy. You should have 2 cups purée. Place in large bowl and refrigerate until completely cooled.
Once cooled, stir in egg and salt. Then add 2 cups flour, mixing until evenly blended. Transfer to lightly floured work surface and gently knead in more flour just until dough is soft and smooth. Divide dough into 2 pieces.
Line baking sheet with parchment paper and dust with flour. On floured board, roll each piece of dough into a long rope, about 16 inches long. Cut rope into 1 inch pieces. If you wish, roll each piece of gnocchi against the tines of a fork for added texture. (This step is optional.) Then place in single layer on floured baking sheet and set aside.
Preheat oven to 275 F. Lightly oil baking dish just large enough to hold salmon in a single layer. Place salmon fillets skin-side down. Rub salmon with oil and lightly season with salt and pepper. Tuck fresh thyme and chopped garlic around fillets. With mortar and pestle, crush saffron until finely ground and place in small bowl. Add 1 1/2 Tbsp hot water to saffron and stir until almost dissolved. Stir in juice from 1 lemon and drizzle overtop salmon. Slow-roast salmon in preheated oven for 15 to 18 minutes, or just until opaque in the center.
While salmon bakes, bring large pot of water to a full boil. Cook gnocchi in batches of 20 or more so they don’t stick together. Cook for 4 to 6 minutes, until they begin to float. Remove with slotted spoon and set aside in heated bowl. Repeat until all gnocchi are cooked.
When salmon is done, remove from oven. Gently lift baking dish, straining any liquid into small saucepan. Whisk in juice from remaining 2 lemons, along with maple syrup, butter, and a bit of fresh thyme. Continue to whisk, just until it appears almost creamy. Add a splash of water, if necessary. Season to taste. Remove from heat and strain sauce over gnocchi. Gently toss to evenly coat.
Serve gnocchi in heated individual serving bowls with salmon fillet overtop and garnish with fresh dill.
Each serving contains: 562 calories; 42 g protein; 19 g total fat (5 g sat. fat); 54 g carbohydrates (1 g sugars, 6 g fiber); 470 mg sodium