1 1/2 pounds Butter Babies™ potatoes, halved lengthwise
2 1/2 to 3 teaspoons kosher salt
1 tablespoon Dijon mustard
2 tablespoons mayonnaise
3/4 cup (5.3-ounce single serving container) plain Greek yogurt
2 tablespoons lemon juice (about 1 lemon; Meyer, if available)
2 tablespoons chopped fresh dill
2 tablespoons chopped fresh parsley
1/4 teaspoon black pepper
1 medium fennel bulb
2 tablespoons minced shallot
Place Butter Babies potatoes and 2 teaspoons salt in saucepan and cover with water. Bring to a boil, then reduce heat to simmer 15-20 minutes until just tender. Drain potatoes and cool.
Trim fennel by removing outer layer of bulb if discolored and any dry or tough pieces of stem. Fronds (or leaves) of fennel can also be chopped and added to salad (looks similar to fresh dill). Slice fennel thinly.
In medium bowl, whisk together Dijon mustard, mayonnaise, Greek yogurt, and lemon juice until smooth. Add dill, parsley, remaining salt, pepper, fennel, and shallots; mix until combined.
When potatoes are cooled, add to yogurt mixture and gently toss until combined. Serve at room temperature, or cover and chill until ready to serve. Will keep about 3 days refrigerated.