自然の中でゆっくり凍った氷の味を楽しんでください。
Please enjoy the flavour of ice slowly made by nature.
If not sure if I should read this as 'ice made by nature' or 'ice made in nature'. The 中 is really confusing me because I normally think of this as inside/among/throughout, none of which really seem to work well here.
The Japanese verb for 'made' does not appear in your sentence. The word frozen is (凍｛こお｝る）.
What does 中 mean? Inside/within. What does 中で mean? Occurring inside/within.
自然 and its English counterpart 'nature' can refer to 'a natural environment'.
自然の中 = in nature, 自然の中で = occurring within nature (natural surroundings)
自然の中で凍った = Frozen within natural surroundings (a natural environment).
