Balsamic Steak With Radicchio

INGREDIENTS

• 1 to 2 teaspoons sugar, plus a pinch
• Kosher salt and freshly ground pepper
• 4 6-ounce beef eye round steaks
• 1 clove garlic, sliced
• 1/4 cup balsamic vinegar (preferably aged)
• 1/2 cup low-sodium chicken broth
• 1/3 cup sun-dried tomatoes, thinly sliced, plus more for topping
• 2 heads radicchio, torn into pieces
• 1/2 cup fresh basil leaves, sliced, plus leaves for topping
• 3 tablespoons unsalted butter