Five-Spice Char Siu

At any given dinnertime I feel like there are at least eight million things I could do with a pork tenderloin. Absolutely marvelous stuff.
I had been going back and forth between two recipes, but settled on this one, in part because I was really craving the soba noodles to go with it. It's one of those things that ends up being more Asian-inspired than Asian itself, but this doesn't bother me - it came remarkably close to the strips of pork hanging in the butcher area at my favorite Asian grocery store, and that's good enough for me.
Be sure to put enough water in the bottom of the pan so the drippings don't burn.

FIVE-SPICE CHAR SIU
adapted from Simple Chinese Recipes

2 tsp five-spice powder
2 Tbsp sugar
2 Tbsp oyster sauce
2 Tbsp hoisin sauce
2 Tbsp reduced-sodium soy sauce
1 tsp chili sauce
2 tsp sesame oil
2 Tbsp light rum
2 Tbsp black bean garlic sauce

2 pork tenderloins, each about 1 lb

3/4 c or more boiling water

Mix the marinade ingredients together. Place the pork tenderloins in a large Ziploc bag and pour in the marinade. Squish it all around to coat and seal, pressing out the air. Refrigerate and let marinade for at least 2 hours.
Preheat the oven to 425 F.
Place the tenderloins in a rack on a baking pan, reserving the marinade. Place the pan on a rack in the oven and pour the boiling water into the bottom of the pan. Roast at 425 for about 15 minutes.
Brush the pork on all sides with the marinade and turn the pork over. Reduce oven temperature to 350 F. Let roast for another 15 minutes.
Turn the oven off and let the pork sit in the hot oven for another 10 minutes. Remove, slice, and serve.