Preheat broiler. Drain tomatoes, reserving oil; finely snip tomatoes. In a small bowl, combine snipped tomatoes, 1 teaspoon of the reserved oil, the ½ cup watercress or parsley, and the pine nuts; set tomato mixture aside.
In a food processor or blender, combine another 1 teaspoon of the reserved oil, the beans, milk, lemon juice, thyme, salt, pepper, and garlic. Cover and process or blend until smooth. Set bean mixture aside.
Place bread slices on a baking sheet. Broil 4 inches from the heat for 1½ to 2 minutes or until bread is lightly toasted, turning once. Remove from oven; cool slightly.
Place about 1 tablespoon of the bean mixture on each of the toasted bread slices, spreading evenly to edges. Broil 4 inches from heat about 1 minute or until bean mixture is warm. Remove from oven. Top each with some of the tomato mixture. If desired, garnish with watercress sprigs. Serve immediately.
Tips: To toast pine nuts, spread in a shallow baking pan lined with parchment paper. Bake in a 350°F oven for 5 to 7 minutes or until golden, shaking pan once or twice.
To make ahead: Prepare as directed through step 3. Cover and chill tomato and bean mixtures separately for up to 24 hours. Place toasted baguette slices in an airtight container; store at room temperature for up to 24 hours. Preheat broiler. Continue as directed in step 4.