How to Make It
Melt the butter in a large skillet over medium-high heat. Add the carrots, mustard seeds, ½ teaspoon salt, and ¾ cup water. Cook, stirring occasionally, until the carrots are just tender and the water has cooked off, 15 to 17 minutes (adding ¼ cup more water to the pan if necessary).
Add the vinegar and dill; toss to combine.