I've found the best way to make instant gorditas, without having to go through all of the hassle of mixing up the masa, rolling it out to the right thickness, cooking, and slitting it to make the pocket for stuffing.
I cook 2 regular corn tortillas on both sides till done, or about done. Then I beat an egg, and either brush egg around the rim on one face of each tortilla, and stick them together, then cook until the egg has set, gluing the two together; or I hold the tortillas vertically, and just rotate them in the egg about 1/2 inch deep, until the rim is coated, stick them together, and procede as above. Of course the second method puts egg on both faces of both tortillas, but it doesn't matter. After cooking, use a sharp knife to gently part a small opening, allowing space through which to stuff the instant gordita. Of course, you may find that a section of the rims haven't "glued" right, in which case you can use this natural opening to stuff through.
For stuffing I use scrambled eggs, cheese, rice, beans, meat, in any combination.
Hugs,