Today’s recipe for marbled yeast bread (I don’t do sourdough) has milk as an ingredient. Is milk a necessity? Jews (at least this Jew) are not supposed to eat milk and meat at the same meal. That would make it impossible to make this bread into a meat sandwich. Can I make this bread (as well as other breads) without milk?

Question about use of a poolish. About two months ago, I made some French bread using a poolish of 100g each of flour/water and .25 tsp. of instant yeast. The French bread was the usual 4 ingredients: bread flour, water, instant yeast, & salt. I let the poolish develop for about 12 hrs. The result was a nice flavor boost. A few days ago, I made some challah rolls using a recipe from King Arthur Flour. I thought that use of a poolish might boost the flavor. I used the same poolish ingredients and process as above. But there was not much of a flavor boost. I wondered if poolish works better with a lean dough like French bread but less well with challah which had several eggs and several tbsps. of canola oil. Thanks in advance for your help.