Sliced Spring Salad with Avocado and Feta

I added chicken to this recipe and had it for lunch. It was a great salad. Instead of Feta cheese, I used goat cheese. It comes from Molly Wizenberg's "A Homemade Life"

For the Vinaigrette
1 Tablespoon Dijon mustard
3 Tablespoons red wine vinegar
1/2 teaspoon salt
5 Tablespoons olive oil, plus more to taste
For the Salad
8 radishes
1 medium radicchio
4 Belgian endive (about 1 pound)
A good handful of cilantro leaves
1 medium avocado
1/2 cup crumbled fench feta, or more to taste
First, make the vinaigrette. In a small bowl, combine the mustard, vinegar, and salt. Whisk to blend well. Add the olive oil and whisk vigorously to emulsify. Taste, and adjust the seasonings as needed. I put my vegetable ingredients on a large serving plate instead of a bowl.
Trim the radishes and slice them very thinly into translucent wafers. Toss them into the bowl. Next quarter the radicchio from stem end to top, and peel away any raggedy outer leaves. Working with one quarter at a time, slice it crosswise into ribbons roughly 1/4 inch thick. Toss the radicchio into the bowl. Next, slice the endive crosswise into 1/4 inth thick strips, discarding the root end. Add it to the bowl. Add the cilantro leaves and toss with vinaigrette to taste. Quarter the avocado from stem to base and discard the pit. Cut each quarter crosswise into 1/4-inch thick strips. Distribute them evenly over the salad and top with the feta. Serve immediately.