cut in refers to using 2 table knives to litterally cut butter into flour mixture. I find it easier to use my God given fingers. I mash the butter or shortening or lard, whichever, into the flour and mix it in at the same time. It comes out looking like there are crumbs in it. Cake mixes have a similar texture. This technique is used for homemade cakes, pizza dough, homemade tortilla's, some breads, and the like. After that step, you add the liquid and then usually knead the dough ball at least a little. Follow your instructions. You don't have to use knives to "cut in" the butter. you can use a mixer with the pastery attatchment but I prefer my hands, I know the dough isn't overworked and I can "feel" that it is ready for the next step. Happy cooking!
Source(s):
Me, cooking since I was 8, about 35 years