Roast Chicken with Kimchi Smashed Potatoes

INGREDIENTS

• 4 tablespoons vegetable oil, divided
• 4 cups trimmed bitter greens (such as mustard, mizuna, or arugula)
• Kosher salt, freshly ground pepper
• 2 garlic cloves, grated
• 1 16-ounce jar Napa cabbage kimchi, drained, 1/4 cup liquid reserved
• 4 large skin-on, bone-in chicken thighs (about 1 1/2 pounds total)
• 1 1/2 pounds fingerling or baby Yukon Gold potatoes
• 1 tablespoon unseasoned rice vinegar