Preheat oven to 375°F. Place salmon in a large rimmed sheet pan lined with foil. Drizzle with the olive oil, then sprinkle with lemon zest, oregano, salt and pepper.
Rub the salmon to incorporate the ingredients and spread them over the fish. Arrange peppers around salmon.
In a large bowl, add the potatoes and zucchini.
Toss with olive oil, a generous pinch of salt and pepper and parsley. Spread the potatoes and zucchini around the salmon on the sheet pan.
Bake everything until salmon is firm but still pink in the center, about 10 minutes for pink in the middle, or 15 minutes for more well done.
If the salmon is finished cooking before the potatoes and zucchini, remove salmon, set aside on a platter and cover loosely with foil to keep warm. Continue cooking potatoes and asparagus until both are easily pierced with a fork and golden brown.
While the salmon, potatoes and zucchini are cooking, whisk oil, lemon juice, honey, mustard, salt, pepper, and 1/4 cup dill in a small bowl or measuring cup.
Toss escarole (or salad mix) with half of the dressing in a large bowl, then transfer to a serving platter.
Toss potatoes and zucchini with remaining dressing in same bowl, then arrange over escarole.
Lay salmon on top of the escarole and top with peppers, dill sprigs, and any other additional toppings -- I love using crumbled feta or goat cheese.
Serve immediately.