Sentence:  In true kosher cooking, meat and dairy should never be combined. <WSD>Pareve</WSD> margarine is made up of 100 percent vegetable oil. Dairy margarine has milk as one of the ingredients plus perhaps added vegetable oil. This is why when cooking a meat or dairy meal, if the recipe requires butter or margarine, I substitute it with <WSD>pareve</WSD> margarine. 
Meaning of the word marked with <WSD> tags:  Of food: that has no meat or milk in any form as an ingredient.