Teriyaki Pot Roast

From a recipe card in Mom's elegant handwriting (don't recall her ever making it, though):

Teriyaki Pot Roast

Combine syrup from 1 lb 4 oz can Dole sliced pineapple with 2 Tbsp soy sauce, 1 Tbsp sugar, 1/2 tsp ginger, 1/8 tsp garlic powder.

Pour over 3 lb boneless chuck roast in large skillet.  Cover and simmer 3 hours, turning occasionally.

Blend 1 Tbsp cornstarch into 1/4 cup water.  Stir into pan juices until thickened.  Stir in pineapple slices and 1/4 cup chopped green onions.