Here is the recipe that I use:
For a 4-6-pound beef brisket or other cut
1/2 cup, kosher (coarse-grain) salt
1 tablespoon, black peppercorns - coarsely cracked
1 tablespoon, brown sugar
3/4 tablespoon, ground allspice
1 tablespoon, dried thyme
1/2 tablespoon, paprika
2 bay leaves - crumbled
3 cloves, garlic - minced
optional (for red color): 1 tablespoon, sodium nitrite* - dissolved
in 1/2 cup, warm water. [*sold in pharmacies or order from butcher shops]
[Vegetables, as desired to serve with corned beef – see last paragraph]
Mix kosher salt with all other seasonings (but not saltpeter) in a small bowl. Pierce the brisket several times on each side with a skewer or heavy fork. (NOTE: this piercing step may be eliminated if meat is cured for 10-14 days, instead of 5-7 days, before rinsing and cooking.)
Rub both sides of meat evenly with salt/spice mixture. Place meat in heavy, 2-gallon size plastic zipper-lock bag, squeezing out as much air as possible before closing bag. [Pour over dissolved saltpeter in water, if using, before sealing bag.] Place bag with meat in a pan large enough to hold it, cover with another pan of similar size, and weight the top pan with two bricks, or with two heavy cans from the pantry.
I do not use the sodium nitrate. A friend uses a tri-tip instead of a briskit but actually just about any cut of beef can be used.
Enjoy!