Use new potatoes (freshly dug, thin-skinned tubers that haven’t been stored) to make this hearty side dish. Look for them at your local farmers’ market. Wash gently; their papery skin scrubs off easily.
| 4 | pounds 1"-diameter new potatoes, preferably red-skinned |
| Kosher salt | |
| ½ | pound good-quality summer sausage, cut into ½" rounds |
| 6 | tablespoons (¾ stick) unsalted butter, cut into small cubes |
| 2 | tablespoons whole grain mustard |
| Freshly ground black pepper | |
| 3 | tablespoons coarsely chopped fresh dill plus more for garnish |
| 2 | tablespoons chopped fresh chives |
Place potatoes in a large pot. Add water to cover by at least 1”; salt water generously. Bring to a boil over medium-high heat; immediately reduce to a low simmer. Simmer potatoes until tender, about 20 minutes. Drain potatoes, reserving ½ cup cooking liquid.
Meanwhile, heat a grill pan over high heat. Add sausage rounds and cook on one side until charred in spots, about 5 minutes (do not grill second side). Let sausage cool. Cut sausage into ½” cubes and set aside.
Combine potatoes, butter, mustard, and 3 Tbsp. potato cooking liquid in a large bowl. Toss, adding cooking liquid by teaspoonfuls as needed, until butter lightly coats potatoes with a glossy sauce. Season potatoes to taste with salt and pepper.
Using a potato masher, lightly crush the potatoes (you want them to just break open but not fall apart). Add 3 Tbsp. dill, chives, and half of sausage; toss once. Scatter remaining sausage over top and garnish with chopped dill.