In the Nepal war of 1812 the British sent a force of 30,000 against 12,000 Gorkhas (in reality at this time there was no such thing as a Gurkha -- they were called Gorkhalis) thinking in their usual arrogance they would take Nepal by storm. Just the opposite proved to be true. The Gorkhas fought the British to a standstill.
For example, during extremely bitter fighting while defending the hill fortress of Kalunga the Gorkhas lost 520 out of 600 defenders but they fought so bravely and so well and the losses they inflicted on the British were so staggering it inspired the British to erect a stone battle monument at Kalunga inscribed with the words:
THEY FOUGHT IN THEIR CONFLICT LIKE MEN AND, IN THE INTERVALS OF ACTUAL CONFLICT, SHOWED US A LIBERAL COURTESY.
But, it was a two way street. In another incident British Lieutenant Frederick Young leading a party of irregulars was surprised by a force of Gorkhas. The irregulars upon seeing the khukuri yielding Gorkha force ran away leaving the British Officers to face the Gorkhas alone.
There was little battle here since the Gorkha force was so superior but the fact that the British Officers had remained to try to hold their ground and had not fled greatly impressed the Gorkhas. They asked Young and his subordinates why they had not also ran away and according to legend Young replied, "I have not come so far to run away. I came to stay." And stay he did. For about a year the Gorkhas held Young captive but during this year the Gorkhas developed a sincere and deep respect for Young and the British fighting spirit which much resembled their own. And, indeed, it was Young himself who was able to recruit the first Gorkhas to serve under the British flag -- 3,000 Gorkhas divided into four battalions. Young went on to serve as the commander of the Sirmoor Battalion of Gurkhas for 28 years and, amazingly, was able to report his battalion service ready after only six months.