4 1/2 pounds pork shoulder, excess fat trimmed, cut into 2-inch pieces
Coarse salt
1 teaspoon fennel seeds, toasted
1/2 teaspoon red-pepper flakes
3/4 cup orange marmalade
1/4 cup red-wine vinegar
1 sprig rosemary
4 cloves garlic, peeled and smashed
2 cups uncooked couscous
2 teaspoons extra-virgin olive oil
2 cups boiling water
1 bunch watercress, tough stems removed, 1/2 cup finely chopped, the rest left in whole sprigs, for serving
Flaky sea salt, such as Maldon, for serving
1 small orange, cut into wedges, for serving