Finely chop the shallots and crush the garlic with a pestle. Mix with the parsley, then season with salt and pepper. Work the butter until it has a smooth, even texture, then fold in the mixture.
Place a small pat of parsley butter in each shell. Add a snail, then generously cover with the remaining butter. Gently smooth the surface.
Arrange the shells in a dish lined with dried beans to keep them standing upright while they cook.
Bake at 240°C for about 8 minutes, until the butter is hot and bubbling.
Serve immediately after removing from the oven and enjoy right away.
