Salmon dalam Foil

Bahan-bahan (2 porsi)

• 2 skin-on salmon fillets
• 2 shiitake mushrooms ((or more if they are thin and small))
• ½ package shimeji (brown beech) mushrooms ((1.8 oz, 50 g))
• 2 inches carrot ((1.4 oz, 40 g))
• ½ onion ((5 oz, 142 g))
• 2 lemon slices
• 1 small bunch chives ((for garnish))
• 1 Tbsp sake ((divided; or use a dry white wine like sauvignon blanc))
• ¼ tsp Diamond Crystal kosher salt
• ⅛ tsp freshly ground black pepper
• 1½ Tbsp unsalted butter ((divided))
• 2 Tbsp ponzu