Kurukshetra is a pilgrimage town, not a food destination. The eating options are largely dharamshalas serving simple vegetarian food to pilgrims — dal, rice, roti, sabzi — and small dhabas clustered around the bus stand and the railway station. Most restaurants serve North Indian vegetarian food (thalis, dal makhani, chole bhature) at very low prices. The quality is honest and filling rather than refined.
There is no drinking culture here; this is an area with a strongly religious character and alcohol is not widely available. The most interesting eating experience in Kurukshetra costs nothing: the free langar (communal meal) served at larger temple complexes, where pilgrims and visitors eat together on the floor. It is worth joining at least once.