Pour the milk and water into a microwave safe bowl. Microwave for 3 minutes or until hot. Stir in the instant potatoes and sazon seasoning, stirring to make sure all the potatoes get wet and don't end up with lumps. Cover and refrigerate for 30-60 minutes to cool.

Dust your hands with flour, and flatten about 1/2 cup of mashed potatoes into a disk in the palm of your hand. Add a heaping tablespoon of picadillo to the center of the disk and bring the edges of the potato up and around the picadillo. Seal the edges and roll into a smooth ball. Repeat until all the potato has been used up, making sure to coat hands in flour each time.

Form a breading station by place your flour into one bowl, the beaten eggs into a second bowl, and the breadcrumbs into a 3rd bowl. Add ½ teaspoon of adobo seasoning each to the flour and breadcrumbs, and stir with a fork to distribute the seasonings.

Roll each potato ball into flour, then beaten egg, and finally into the breadcrumbs. Refrigerate the breaded potato balls for 30 minutes to give them a chance to firm up.

Preheat your oil to a deep fryer to 375 degrees F.

Fry the rellenos a few at a time, until they're golden brown and crunchy. Let them rest for 3-5 minutes before serving, they're hot!