Solar cooking was mentioned in the Jewish holy scripts of the Mishna (compiled circa. 200 BC to 100 AD) written in Hebrew. The texts refer to the Mishnaic and Talmudic discussions on whether solar cooking was allowed on the Sabbath day (Saturday), when cooking or creating a fire is not permitted, stating that cooking done by the sun would be permitted on the Sabbath. They state that solar cooking is the “produce of the Sun, not produce of man-made fire”.
In orthodox Jewish “Rabbinic” writings on Jewish rituals, this topic is discussed at length, especially due to the mandatory solar water heaters on every roof in Israel. Several orthodox Ashkenazi Jews have often used the sun as a solution for warming lunch at noon, which otherwise would be prohibited according to their customs. This applies only to dry foods, and only if the heat is received directly from the sun rays, and not by passing the heat and warmth via any other material (such as warm sand).
Excerpt from https://solarcooking.fandom.com/wiki/Israel
Please see the discussion with Rav David Barak (Hebrew and English) about if it is permitted to use solar cooking on Shabbat:
האם מותר לבשל בתנור סולרי בשבת
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