Heat olive oil in a saute pan over medium-high heat. Add the onions, red and yellow peppers and jalapeño, then add some salt and pepper to taste, and cook, stirring, until translucent, 6 to 8 minutes. Add the pineapple, honey, mustard seeds and lime zest and juice and cook until the sauce reduces and becomes thick in consistency, 5 to 8 minutes more. Remove from heat and add chopped fresh herbs to finish.
Preheat grill to 450 to 500 degrees F.
Grill hot dogs until they have nice grill marks. Meanwhile, grill the hot dog buns.
Place hot dogs in the buns and spoon pineapple relish on top.