Here is what you need:
2.5 lbs of potatoes. I use thin skin yellow potatoes but red potatoes would work well also.
1 cup low fat/fat free quark/greek yogurt
salt and pepper to taste
Note: You can obviously split the amounts above for smaller portion size, the 2.5 lbs potatoes make roughly 5 servings.
Slice potatoes in to equal size pieces. Place in a large pot with salted water and bring to a boil. Reduce the heat some and continue cooking until potato pieces are fork tender, about 10-15 minutes. Don't let them overcook or you will have watery mashed potatoes. Once they are done cooking drain them well.
I typically use my mixer to make these, but you can also use a hand masher if you don't have a mixer. Place potatoes in the mixing bowl, add quark and salt and pepper. Mix on low to get things started and then increase speed slowly. Once your desired consistency has been reached, they are done!