5 venues in Groningen rated S to B for vegetarian, every tier backed by cited sources.
The entire kitchen is dedicated to vegetarian cooking - no meat or fish is ever used on the premises. Every dish is vegetarian by default, so cross-contamination from meat or fish is impossible.
The entire menu is vegan, making it vegetarian-friendly as well. No meat or fish is used anywhere in the kitchen.
Lust is a 100 percent vegan restaurant. Because the kitchen contains no animal products, every dish is automatically vegetarian. No per-dish markings indicate vegetarian status, but the entire menu qualifies. Like the vegan claim, no independent verification of the vegetarian claim exists beyond the venue's own assertion.
The official menu marks vegetarian dishes with a Thai symbol, and the restaurant offers many vegetarian options. Staff are reported as knowledgeable about vegan options, which likely extends to vegetarian ones. Shared kitchen so cross-contamination is possible for strict vegetarians. Generally reliable.
The dinner menu marks vegetarian dishes with a (V). Staff can provide an allergen chart, which suggests they are able to accommodate dietary needs. No information is available about dedicated preparation or cross-contamination controls for vegetarian items.