Preheat the oven to 400°F and coat a baking sheet with nonstick spray.
Make the dressing by whisking the olive oil, lemon juice, mayonnaise and mustard together until smooth. Season to taste with salt and pepper, then stir in the dill. Cover and set aside until serving time. If using canned salmon, skip to step 4.
Season the salmon on both sides with salt and pepper and bake until the fish flakes easily, 8 to 10 minutes. Transfer the salmon to a mixing bowl, wipe off the baking sheet and re-coat with nonstick spray.
Flake the salmon with a fork and let it cool for about 5 minutes.
Add the quinoa, egg, mayonnaise, dill, mustard, shallot and lemon juice and combine well.
Form the salmon mixture into 8 patties and arrange them on the prepared baking sheet (see tip below).
Bake until the salmon patties are crisp and lightly toasted, 12 to 15 minutes.
Serve patties with a green salad, drizzle with dill dressing and garnish with lemon wedges if desired.
Notes
If you have the time, chilling the salmon mixture for about 15 minutes prior to making the patties will make it easier to work with.