Soak bulgur in cold water 10 minutes. Drain in a sieve lined with damp cheesecloth; squeeze out all water. Transfer to a serving bowl; fluff with a fork.
Stir in tomatoes with juice, parsley, and scallions. Add lemon juice, salt, and oil; season with pepper. Toss to coat. Just before serving, stir in mint.
Mint is optional. Martha prepared bulgur as follows: In a medium saucepan, bring 3 cups water, bulgur, and 1/2 teaspoon salt to a boil over medium-high heat, stirring often. Reduce heat to medium-low, cover, and simmer until tender, 10 to 12 minutes. Drain well; transfer to a serving bowl. Fluff with a fork and let cool completely.