Preheat oven to 425 degrees F. Place large sheet of foil on baking sheet. Drizzle a little olive oil on the foil & spread evenly. Mix shallots, garlic, onion, capers and dill in small bowl. Place salmon on foil; coat with mustard, then sprinkle with lemon-pepper seasoning. Spread shallot mixture over salmon. Dot with butter. Fold up foil edges to enclose salmon; seal. Bake salmon just until opaque in centre, about 25-30 minutes. Open foil; transfer salmon to platter. Spoon any juices over. Garnish with lemon wedges