Over medium heat, heat oil on pan, then the butter until melted. Add the prawns. Sprinkle with freshly ground pepper as desired and cook for 10 minutes or until they change color; add the chopped garlic and sauté.
Separately, blend chipotles, cream, shrimp concentrate and milk until well mixed.
When prawns are sautéed, add the chile mixture. Cover and simmer for 5 minutes.