Clean the green beans by trimming off the stem end (not the other end).
Blanch the green beans in a large pot of salted boiling water until they are just tender, but still crunchy, 3 to 5 minutes. Taste them frequently. you can watch the color turn from lighter to darker, but the best way is to taste them frequently.
Once cooked, quickly transfer the green beans to a bowl of ice water using a spider or tongs. This will quickly stop the cooking and preserve the bright green color.
To finish cooking the green beans right before serving; place the butter and chopped shallot in a skillet over medium heat, cooking until the butter is melted and the shallot starts to turn translucent, about 1 minute
Add the green beans, stock, and season with salt & pepper.
Heat through and serve.