Preheat oven to 400°. Bring a large pot of salted water to boil, add potatoes and cook for 15-20 minutes or until very tender. Drain and return to pot.
Meanwhile, heat extra virgin olive oil in a large skillet over medium heat. Add chard or kale and cook, stirring occasionally, until softened and starting to lightly brown, about 3-5 minutes. Remove from heat and transfer to a bowl. Reserve skillet.
Melt 1 tbsp butter in a small bowl. Add Irish whiskey and honey, and whisk together.
Place salmon skin side-down in the skillet and pour whiskey glaze over the top. Sprinkle with salt and pepper. Bake for 5 minutes then remove and spoon sauce from the pan over the top of the salmon. Return to oven and bake for 3-6 minutes, until fish flakes easily with a fork and internal temperature of 125-130° (or 145° if you prefer well-done).
Heat milk to a simmer in a small saucepan over medium-low heat. Meanwhile, mash potatoes until fairly smooth. Add 3 tbsp butter and milk and stir until butter is melted. Add more milk as needed if mashed potatoes are too thick. Add chard, ½ tsp salt, and ¼ tsp pepper. Adjust seasoning to taste.
Divide mashed potatoes onto plates and top with salmon. Sprinkle with parsley and serve.