vegetarian broccoli cheese soup

INGREDIENTS
1/4 cup butter
1 onion, cut into medium dice
2 teaspoons garlic powder
1/2 teaspoon ground white pepper
1 (16 ounce) package frozen chopped broccoli
1 quart vegetable broth
1/2 cup all-purpose flour
1 1/2 cups whole or 2% milk
salt to taste
8 ounces shredded sharp Cheddar cheese

DIRECTIONS
Melt butter over medium heat in a stockpot. Cook onion in butter until softened. Add garlic and pepper; cook for 1 minute then stir in broccoli, and stir in broth. Bring to a boil and simmer until broccoli is tender, 10 to 15 minutes.
Meanwhile whisk flour into milk until dissolved. Stir into soup stirring frequently until thickened. Reduce heat, and stir in cheese until melted and heated through.
Season with salt to taste.