Rinse arugula. Run through salad spinner. Spread out on paper towel to dry.
Make dressing: In a small bowl, add shallots, garlic, and vinegar. Slowly drizzle in olive oil, whisking all the while, until mixed. Add salt & pepper to taste. Or, put everything into a jar. Seal. Shake.
Pat dry the arugula leaves. The drier your lettuce leaves, the better the dressing sticks to them.
Add arugula to a large mixing bowl. Pour 1/3 c of dressing over leaves. Toss, until all leaves are coated with dressing. Add more, if necessary.
Divide dressed arugula leaves onto four plates.
Divide sliced fennel bulb and chopped fennel tops evening between all four salads. While the bulb has a mild flavor, the greens are quite strongly flavored. Just a little will do.
Top each salad with 2 oz sliced strawberries, 1 oz walnuts, and 1 oz feta cheese.
Serve extra dressing on side.