Dill-Cured Pork Crostini with Sweet Mustard Sauce

Mix salt, 3 tablespoons sugar, and pepper in small bowl to blend. Place each pork tenderloin atop sheet of plastic wrap. Rub garlic all over pork tenderloins. Pat all of salt mixture over pork, coating generously. Sprinkle with 3/4 cup dill, patting to adhere. Wrap pork with plastic. Place in baking dish. Chill 6 hours. Preheat oven to 400°F. Scrape off some of dill coating from tenderloins. Pat pork dry with paper towels. Place pork on heavy large baking sheet. Roast until meat thermometer registers 150°F when inserted into center of pork, turning after 15 minutes, about 25 minutes total. Cool pork completely. Cover and chill until cold, at least 6 hours. Stir remaining 1/2 cup sugar and vinegar in small bowl until sugar dissolves. Whisk in mustard. Stir in remaining 2 tablespoons dill. Season sauce to taste with salt and pepper. Cover and refrigerate until cold. (Pork and sauce can be made 1 day ahead. Keep refrigerated.)Cut pork crosswise into very thin slices. Arrange pork atop baguette slices. Spoon some dill sauce atop each. Arrange on platter and serve.