Step 1In a medium saucepan, combine 3 cups of the milk and the gelatin. Set the mixture aside for 10 minutes. Put the remaining cup of milk in a medium bowl with the vanilla bean. Place the medium bowl in a larger bowl filled with ice water.
Step 2Heat the milk and gelatin mixture in the saucepan over high heat just until the gelatin has dissolved and the mixture is hot, about 2 minutes, stirring frequently. Remove from heat and add the sugar and salt. Continue stirring until the sugar and salt have dissolved.
Step 3Pour the warmed milk mixture into the bowl set over the ice bath, stirring to combine with the chilled milk. Continue stirring gently until the mixture has thickened, 10 to 15 minutes. Strain the mixture, discarding the vanilla bean, then pour it evenly into each of 8 (4-ounce) ramekins. Cover each ramekin with plastic wrap and refrigerate until set, several hours to overnight.
Step 4Unmold the ramekins before serving: Dip each ramekin, one at a time, into a bowl of hot water to loosen the sides and bottom. Carefully invert each ramekin over a serving plate when unmolding. Garnish each plate with the chopped fruit before serving.