Cutting the bake short by even 15 minutes leaves the pepper walls underdone — the filling is already cooked, so all that remaining time is for the peppers. Both rounds of baking are essential.
One cup dry makes more cooked rice than the filling needs. Add it gradually and stop when the filling is saucy and cohesive. Too much rice makes it starchy and dry.
A small can wasn't quite enough — a full 15 oz can gives the filling the moisture it needs, especially since the rice absorbs a lot of it during baking.
Swapping half the ground beef for chorizo adds smoky, spiced depth you can't get from seasoning alone. Remove from the casing and crumble it right in with the beef — no need to cook it separately.
Red peppers are sweeter and hold up beautifully in the oven. Green adds a slight bitterness that balances the richness of the chorizo. The color contrast on the table doesn't hurt either.