How To Cook On Shabbos

How to cook Shabbos morning, fresh chicken soup      1) One may not cook with תולדות חמה. e.g. Cooking an egg in a pot that was heated up by the sun. (egg heated by the pot) 2) One may cook with חמה e.g. Placing an egg under the sun. (egg heated directly from the sun) *According to Mori V'Rabi Harav Hagaon R. Shlomo Miller Shlita, One may place food under the sun and have a magnifying glass directed at the food (not at the pot). Since the food is being cooked directly from the sun it's בישול בחמה which is permissible on Shabbos. All the magnifying glass does is it increases more sun onto the food.   PS: creating a fire on Shabbos with a magnifying glass is prohibited  *ספר שבת שלמה מאת ידידי הרה"ג עזריאל יהודה געשטעטנר שליט"א