St. Patrick Sandwich

A green herb sandwich built for colour as much as flavour, and one of the shortest recipes in the book. The mint is the point, not a garnish, so treat it as a lead ingredient.

• What a "handful" meansRead it as a loosely packed cup of leaves, which chops down to roughly 2 to 3 tablespoons of each herb. Equal parts mint and parsley is bracingly minty; if that worries you, weight the mix toward parsley and add mint to taste.
• Herbs, not pasteChop with a sharp knife and stop while the pieces are still distinct. A food processor bruises mint and parsley into a wet green sludge that bleeds into the butter and turns the bread grey.
• The onion"A tiny onion" means something the size of a walnut, about a tablespoon minced. A shallot or the white of a spring onion is closer to the intended mildness than a supermarket yellow onion, which will dominate the mint.
• Paprika in 1909The paprika sold in America at this date was generally sweet, most often Hungarian, and here it is doing as much work for its red flecks against the green as for its flavour. Smoked paprika was not part of the American pantry then and will pull the sandwich somewhere the recipe never intended.
• MayonnaiseAdd it a teaspoon at a time until the herbs just cling together. Too much and the filling slides out of the bread. Homemade mayonnaise here is uncooked egg, so use a commercial jar, or pasteurised eggs, if you are feeding anyone vulnerable.
• Why the butter mattersThe thin layer of butter on each slice is a moisture barrier between wet filling and soft crumb. Skip it and the bread is damp within twenty minutes.
• Bread and trimmingA close-grained white sandwich loaf, sliced thin, is what is meant. Assemble, press lightly, trim the crusts, then cut into triangles or fingers; cutting before trimming tears the edges.
• Holding and yieldThe mixture can be made an hour ahead and kept covered in the refrigerator, but assemble no more than 30 minutes before serving. The recipe gives no yield; as a rough estimate one batch will fill something like 6 to 8 sandwiches, or upwards of twenty tea-sized fingers.