"Researchers found evidence for garlic mustard in the residues left on ancient pottery shards discovered in what is now Denmark and Germany." The shards date back about 6000 years, according to a piece by the BBC.
The (University of) York scientist ( Hayley Saul) said it was likely that prehistoric chefs would have crushed the seeds: "Actually to get the flavour out you have to crush it really. I suspect that if they hadn't been crushing the seeds, we would probably find more intact seeds in residues."
Although this is the first evidence of spice use in Europe, flavouring food may have been a common practice in the Middle East much earlier. "There's a cave in Israel where coriander has been found, and that's dated to around 23,000 years ago. But it's very difficult to build up a picture of exactly how it's used. It's linking it to cooking that's quite important," explained Dr Saul.