What fat content would you use if you used ground beef so that it's flavorful but not dripping with grease?

I really haven't read this recipe, so I'm unaware of the spices/herbs that will be used. In most everything I cook that uses ground beef, though, I generally use a 2/3:1/3 ratio of 80/20 ground chuck to 90/10 ground sirloin. The 80/20 ground chuck gives the great flavor of chuck along with enough fat to help the batch cohere and to not stick as badly to the grill or pan as low-fat ground beef alone. The 90/10 sirloin adds some additional steak-ish flavor to the dish.

Thanks y'all!

I use 20/80 for standard burgers. I go 10/90 if I plan on adding fatty or greasy toppings like bacon or caramelized onions.

You can go as lean as the tag describes...but, you can add back fat in the way of minced bacon, fois gras, pork or other sausages for delicious flavors.

The standard "hamburger" grade is 80/20, meaning 20% fat. If you go with grass fed beef it will be leaner. But when you go too lean you also sacrifice flavor. That's the trade off.

I use 96% lean or bison.

I would use the leanest ground beef you can get, maybe a 90% lean. There are plenty of seasonings and flavorings in the recipe for a flavorful dish.