Preheat the grill. Prepare the smoker. Season both sides of the salmon with salt and pepper. Place on the smoker and cook for about 8 to 10 minutes for medium rare. Remove from the smoker and cool. Season both sides of the onion rings with the olive oil, salt and pepper. Place on the grill and cook for 2 to 3 minutes on each side, or until the onions are soft. Remove from the grill. In a large saute pan, over medium heat, render the bacon until crispy, about 6 to 8 minutes. Remove the bacon with a slotted spoon and drain on paper towels. Add the spinach to the bacon fat. Season with pepper. Saute until the spinach is wilted, about 2 minutes. Set aside, keeping warm. Bring a pot of salted water to a simmer. Add the vinegar. Carefully crack the eggs into the water. Cook until the whites are firm and the yolk is still soft. Remove with a slotted spoon and drain on paper towels. Season with salt and pepper. Flake the salmon into small pieces. To assemble, place the spinach in the center of each plate. Lay the onions over the spinach. Place the salmon over the onions. Lay the 2 poached eggs on top of each layer of onions. Sprinkle the bacon over the eggs. Garnish with parsley. Serve warm.