食材 and 料理: ingredients and prepared food
Distinguish ingredients, finished dishes, and the activity of cooking.
The scope of ingredients
食材 (しょくざい) means ingredients used to prepare food. 「冷蔵庫にある食材を使います」 says the speaker will use ingredients in the refrigerator.
「食材を買ってから帰ります」 places buying ingredients before going back, not after returning.
Food and the activity of cooking
料理 (りょうり) can mean prepared food or cooking as an activity. 「この料理は辛いです」 evaluates a dish as spicy.
「週末に料理をします」 means cooking at the weekend. 料理をする describes an activity rather than one specific finished dish.
Relating input to result
「同じ食材で違う料理を作りました」 means making different dishes with the same ingredients. Identical ingredients need not produce identical dishes.
「料理の写真を撮りました」 says that someone photographed the food. Do not expand this into photographing the purchase of every ingredient without context.
Does 「同じ食材」 necessarily mean 「同じ料理」?
Show the answer and why
No. The same ingredients can produce different dishes through different methods or combinations.