Red Onion and Gorgonzola Flatbread

INGREDIENTS

package (1/4 oz.) active dry yeast

2 cups

all-purpose flour

About 1 cup semolina flour

4 tbsp

olive oil, divided

2 tsp

salt, divided

medium red onion

1 tbsp

fresh rosemary leaves, minced

2 tbsp

balsamic vinegar

1/2 tsp

red chile flakes

4 oz

gorgonzola or other blue cheese, crumbled