You can, but like any other restaurant, Lambert's may charge you double for the entree. Lambert's, Home of the th'owed rolls, is a bit different as restaurants go. It is similar to family style serving, in that pass arounds (side dishes) are complimentary. Although patrons can order pass arounds as their entree and have, essentially, all you can eat. Lambert's is a business nonetheless, and they have the right to make their money fairly, and while they may serve a customer who ordered a beverage his own fill of pass arounds, charging for only the beverage (I've seen this), there is the expectation that those who patron, pay.
On a side note, the Lambert family are wonderful, giving people. Norman has been a star of the show for as long as I can remember. They have treated me and mine like family for as long as I have been fortunate enough to eat there. If you go to any of their locations, treat them as fairly as they will definitely welcome you.
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