We like this recipe to make a low-fat version of this Tex-Mex staple. The recipe calls for ground turkey and reduced-fat sour cream to cut the calories. The recipe also cuts calories by recommending serving this with baked tortilla chips instead of the commercial deep-fried tortilla bowl from take-out places. This recipe appeared in Eating Well June/July 2006. We generally use the same filling for tacos. Family consensus is 93% lean ground turkey tastes best.
Here’s the web link. Of course, you could substitute lean ground beef.