In a medium skillet, bring ¼ cup water and 1 Tbsp oil to a simmer. Add Brussels sprouts, season with salt and cook, covered, stirring occasionally, about 5 minutes.
Meanwhile, in a small bowl, whisk together honey, vinegar, mustard, pepper and red pepper flakes.
Uncover skillet, increase heat to medium-high, and cook until water has evaporated, about 2 minutes. Drizzle remaining oil over Brussels sprouts, add garlic, and cook, tossing occasionally, about 2-3 minutes until Brussels sprouts are golden brown and tender.
Add honey mixture and cook 1 minute. Toss with pepitas if desired. Serve hot!