Notes: This sandwich is a specialty of Hoi An, a charming old fishing village in central Vietnam. Its interplay of textures - cold cuts (pork loin, ham, or chicken; home-cooked or purchased), ground pork, greens, and cucumbers - is distinctive. Choose a sweet baguette with a light, slightly soft interior and thin, crisp crust. You can assemble the sandwiches through step 2 up to 1 hour ahead; cover loosely and let stand at room temperature.
1 teaspoon Chinese five spice (or 1/4 teaspoon each ground cinnamon, ground cloves, ground ginger, and anise seeds)
1 tablespoon salad oil
1/4 cup chopped shallots
1 clove garlic, peeled and minced
12 ounces ground lean pork
3 tablespoons soy sauce
1 1/2 teaspoons sugar
3 baguettes (8 oz. each; see notes)
About 2 tablespoons Asian red chili paste or sauce
8 ounces thinly sliced roast boned, fat-trimmed pork loin or cooked ham or chicken (see notes)
2 cups thinly sliced English cucumbers (about 8 oz.)
3 cups salad mix (4 oz.), rinsed and crisped
1/2 cup fresh Thai or regular basil leaves, rinsed and cut into 1-inch pieces
In an 8- to 10-inch frying pan over medium-high heat, stir five spice until fragrant, about 30 seconds. Stir in oil, shallots, and garlic. Add ground pork and stir often, breaking apart with spoon, until meat is crumbly and no longer pink, about 15 minutes. Add soy sauce, sugar, and salt to taste.
Cut baguettes in half crosswise, then split lengthwise almost all the way through, leaving halves attached at one side. Spread about 1 teaspoon chili paste on one cut side of each baguette section. Spoon about 1/6 of the warm ground pork mixture, including juices, over chili paste. Tuck 1/6 of the pork slices evenly into each sandwich. Set sandwiches slightly apart on a 12- by 15-inch baking sheet.
Bake in a 375° regular or convection oven just until filling is warm and crust is crisp, about 5 minutes. Remove sandwiches from oven and fill each with 1/6 of the cucumbers, salad mix, basil, and Fried Shallots. Add more chili paste and salt to taste.