Prepare the Spicy Relish: Combine apple cider vinegar, water, sugar, salt, mustard seed, and coriander seed in a saucepot.

Bring to a boil over medium-high heat, stirring occasionally, until reduced by half (about 20 minutes).

Add diced cucumber, white onion, thinly sliced serrano chiles, diced red bell pepper, and thinly sliced garlic to the pot.

Continue to boil the mixture until the vegetables have softened and the liquid has reduced to a syrupy glaze (6 to 8 minutes more).

Set the relish aside to cool completely.

Make the Kebab Dogs: In a large mixing bowl, mix together ground pork, chopped mint, cumin, coriander, allspice, salt, and ground pepper.

Divide the pork mixture into 4 equal parts.

Form each part into a tube approximately 7 inches long and 1 inch wide.

Place a long wooden skewer lengthwise through the center of each kebab.

Heat a grill pan or grill to medium-high heat.

Coat each kebab with canola oil on all sides.

Place the kebabs on the hot grill to cook, untouched, for 3 to 4 minutes.

Turn the kebabs and continue to cook until it reaches an internal temperature of 160 degrees F and is cooked through (about 3 to 4 minutes more).

Allow the cooked kebab dogs to rest for 5 minutes.

Remove the skewers from each kebab.

Serve in buttered and toasted hot dog buns, topped with a couple of tablespoons of spicy relish.