Bring quinoa and vegetable broth to a boil in a saucepan over medium-high. Reduce heat to medium-low, cover, and cook for 15 minutes, or until liquid is absorbed and quinoa fluffs with a fork. Transfer to a large mixing bowl; set aside.

Heat 1 Tbsp. of the oil in a large nonstick skillet over medium. Add Brussels and shallots; cook for 7 to 8 minutes, until golden-brown and softened. Add to bowl with quinoa.

In a small bowl, combine remaining 1 1/2 Tbsp. oil, orange juice, vinegar, mustard, salt, pepper, and thyme; stir with a whisk.

Cut the radicchio head in half lengthwise. Remove the core from the radicchio head, and gently break into separate leaves. Add radicchio, apple, and orange-thyme vinaigrette to the bowl with quinoa; gently toss to combine. Top with pepitas and goat cheese.