Cooking chicken soup, Shabbos morning

Parshas Hashava ויקהל                                                                                                                                   'שבת שבתון לה Fresh chicken soup cooked on Shabbos morning      1) One may not cook with תולדות חמה. e.g. Cooking an egg in a pot heated 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 & is permissible even לכתחילה on Shabbos. All the magnifying glass does is increase 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