Bring a large pot of heavily salted water to boil. Add potatoes and boil for 15 minutes, until soft. Drain water and set aside.
Melt 2 tablespoons butter in a large saucepan over medium heat. Add garlic and cook for 30 seconds, then stir in kale and cook until it wilts, about 5-7 minutes.
Once potatoes have cooled, mash them with a potato masher. Stir in remaining butter, vinegar, milk, salt, and Parmesan. Add kale and garlic to the potatoes and stir to mix. Adjust seasoning to taste.
For the salmon:
Turn broiler on high.
Place salmon on a baking sheet skin side up. Rub olive oil and salt into the skin, then broil for 10-12 minutes, until skin starts to bubble.
Recipe by Things I Made Today at https://www.thingsimadetoday.com/2012/11/21/salmon-with-kale-mashed-potatoes/