Sup Daun Bawang Kentang

Bahan-bahan (8 porsi)

• 2½ lbs Yukon gold potatoes ($3.02*)
• 3 Tbsp salted butter ($0.33)
• 1 Tbsp olive oil ($0.18)
• 2 leeks (minced, (1½ lbs untrimmed) $2.39)
• 3 g arlic cloves (minced, $0.12)
• 1 tsp salt ($0.01)
• 1 tsp black pepper (freshly cracked, $0.05)
• 1 sprig fresh thyme (or ½ tsp if using dry thyme, $0.09)
• 1 bay leaf ($0.14)
• 1 tsp apple cider vinegar ($0.01)
• 6 cups vegetable broth ($0.54**)
• 1 cup heavy cream (room temperature, $1.32)
• 1 g reen onion (minced, $0.12)
• 1 -2 Tbsp cornstarch (optional, (as needed) $0.14***)