Pineapple Pork Stir-Fry

I've been sitting on this recipe forever, for no good reason except that I'm lazy and I've never wanted to be bothered cutting up the pork.  It's easiest to cut if you put the tenderloin in the freezer for about 30 minutes.  If it looks a little runny, that's because I ran out of cornstarch the day before.  I would like to try it again with the cornstarch.

Pineapple Pork Stir-Fry
from Taste of Home

1 can (8 oz) unsweetened pineapple chunks, undrained
3 tbsp cornstarch, divided
1 tbsp plus 1/2 cup cold water, divided
3/4 tsp garlic powder
1 pork tenderloin (1 lb), cut into thin strips (cut into medallions, then slice 2-3 strips)
1/2 cup soy sauce
3 tbsp brown sugar
1/2 tsp ground ginger
1/4 tsp cayenne pepper
2 tbsp canola oil, divided
4 cups fresh broccoli florets
1 cup fresh baby carrots, sliced in half lengthwise
1 small onion, cut into wedges
Hot cooked rice for serving

Drain pineapple, reserving 1/4 cup juice; set aside.  In a small bowl, combine 2 tbsp cornstarch, 1 tbsp water, garlic powder and 1 tbsp reserved pineapple juice.  Pour into a large resealable bag and add the pork slices.  Turn to coat evenly.  In a small bowl, combine the soy sauce, brown sugar, ginger, cayenne, 1/2 cup water, 1 tbsp cornstarch and reserved pineapple juice until smooth; set aside.  In a large skillet or wok over medium-high heat, stir-fry pork in 1 tbsp canola oil until no longer pink; remove and keep warm.  Stir-fry the broccoli, carrots and onion in remaining oil until tender.  Stir cornstarch mixture and add to the pan.  Bring to a boil; cook and stir for 2 minutes, or until thickened.  Add pork and pineapple; heat through.  Serve on top of rice.