This recipe was taken from the Internet and after reading it, Jan "tweaked" it before she made   it the first time and we were very happy with the results of that "tweaking".  The original recipe   called for 12 oz. of pasta.  She only cooked 8 oz. of pasta and finally only used about 6 oz. of   the cooked pasta.  If you like a lot of pasta, use what you like but definitely not more than the   amount called for in the original recipe, (12 oz.).  We like more sauce, so we cut the amount of   pasta down as mentioned above.  The second thing that was changed is that she added   mushrooms.  You can use one 4 oz. can of mushroom pieces, with the big pieces being   chopped, or you can add 6 to 8 oz. of fresh, sliced mushrooms to the meat as it cooks.  Cook   the meat until it is browned, and the mushrooms have lost their water and are also slightly   browned or you can omit the mushrooms.  We like mushrooms.  Did I mention Velveeta?  This   cheese was always in our refrigerator as we were growing up.

  Bowtie Pasta With Beef And Velveeta Cheese