Preheat the oven to 350 degrees F.

Spread the walnuts on a small baking sheet and toast until fragrant and lightly colored, 5 to 6 minutes. Let cool then roughly chop. Set aside.

Cut away the peels from the oranges. Over a small bowl, segment the oranges, catching any juices.

In a large bowl, combine the greens, orange segments, and shallot rings.

In a small bowl, add the oil, vinegar, salt, pepper, sugar, and 1 tablespoon of the reserved orange juice and whisk to combine. Pour over the salad, tossing to coat evenly. Add the goat cheese and walnuts and toss. Adjust the seasoning, to taste, and serve.