You'll want to replace the weight of the egg whites (3 egg whites = 96 grams) with water but subtract the amount of weight the two additional egg yolks add (2 yolks = 36 grams) from the water. So 96 - 36 = 60 grams of water. So instead of 100 grams water, you'll have 160 grams (~4 tablespoons) water. You may need to adjust with more or less water depending on humidity, etc. You may also want to boil them for less time (30 seconds per side) so that they're firmer and more bagel-like.