Slashed Chicken with Herb Butter

INGREDIENTS

• 8 Tbs. (1 stick) unsalted butter, at room temperature
• 1 Tbs. chopped fresh flat-leaf parsley
• 1 Tbs. chopped fresh chives
• 1 tsp. chopped fresh chervil
• 1 tsp. chopped fresh thyme
• 1 tsp. lemon zest
• 1 tsp. salt, plus more, to taste
• 1/2 tsp. freshly ground pepper, plus more, to taste
• 1 chicken, 3 to 4 lb.
• 2 bay leaves, cut in half
• 2 garlic cloves, sliced