Guacamole-Stuffed Tomatoes

Cut a 1/4-inch-thick slice from the stem end of each tomato. Using a spoon, carefully scoop out the tomato pulp, leaving a 1/4- to 1/2-inch-thick shell. Discard seeds. Cut a very thin slice from the base of the tomatoes so they sit upright. Set tomatoes, open sides down, on paper towels until ready to stuff. Chop enough of the tomato pulp to measure 1/3 cup; discard remaining pulp.

In a medium bowl mash avocado slightly; stir in chopped tomato pulp, onion, the snipped cilantro, the lemon juice, garlic, and salt. Stuff avocado mixture evenly into tomato shells. If desired, garnish with fresh cilantro leaves.