Tech Priest Chow provides all the carbohydrates and electrolytes needed for even an Electro Priest to function at full capacity for a single day.
Servoskulls need only a fraction of this, but the larger the batches it is made in, the lower the cost.
This nutritional slop is also fit for feeding Servitors, Skitarii, and low level Guardsmen as one sees fit, though even the meager cost of $2 a day may be too much to bear for the enterprising Tech Priest stuck around such filthy biological beings.
https://vocaroo.com/i/s0Z4b51DYywC