From the invaluable The Manhattan: The Story of the First Modern Cocktail.

1-2 oz rye (to taste) 1 oz dry vermouth ½ oz grenadine ½ oz lemon juice 1 dash orange bitters Cherry or lemon peel for garnish

Shake with ice, strain into a chilled coupe. Garnish.

I used Sugar House rye aged in Malbec barrels; Dolin dry vermouth; & BG Reynolds grenadine.