Fire up your grill for medium-high heat. Place a griddle or a large cast iron pan over the highest heat.
Toast buns as desired. You can do this on the grill or however you desire.
Add the balls of ground beef to the griddle. Let them cook untouched for 2 minutes then flatten out with a spatula or burger press.
Season the tops liberally with salt and pepper and cook another minute.
Flip the patties and season again.
Let the patties cook until you start to notice a little char along the edges.
Top patties with the Velveeta and let cook another 30 seconds to melt the cheese. For maximum Velveeta meltiness, cover with the dome to speed the process.
Divide BBQ sauce between the cut sides of the buns. Don't be shy!
Remove the patties and place on bun bottoms.
Add red onions.
Devour immediately.
Notes
After you make a few smash burgers the process becomes very easy and always delivers great results.