This is by many considered superior to caper sauce and is eaten with boiled mutton. It is made with the green seeds of nasturtians, pickled simply in cold vinegar.
Cut about six ounces of butter into small bits, and put them into a small sauce-pan. Mix with a wine-glass of water, sufficient flour to make a thick batter, pour it on the butter, and hold the sauce-pan over hot coals, shaking it quickly round, till the butter is melted. Let it just boil up, and then take it from the fire. Thicken it with the pickled nasturtians and send it to table in a boat.
Never pour melted butter over any thing, but always send it to table in a sauce-tureen or boat.
WHITE ONION SAUCE.—
Peel a dozen onions, and throw them into salt and water to keep them white. Then boil them tender. When done, squeeze the water from them, and chop them. Have ready some butter that has been melted rich and smooth with milk or cream instead of water. Put the onions into the melted butter, and boil them up at once. If you wish to have them very mild, put in a turnip with them at the first boiling.
Young white onions, if very small, need not be chopped, but may be put whole into the butter.
Use this sauce for rabbits, tripe, boiled poultry, or any boiled fresh meat.
BROWN ONION SAUCE.—
Slice some large mild Spanish onions. Cover them with butter, and set them over a slow fire to brown. Then add salt and cayenne pepper to your taste, and some good brown gravy of roast meat, poultry or game, thickened with a bit of butter rolled in flour that has first been browned by holding it in a hot pan or shovel over the fire. Give it a boil, skim it well, and just before you take it off, stir in a half glass of port or claret, and the same quantity of mushroom catchup.