Spicy Beans and Franks for Two

Melt butter in a large skillet over medium heat. Stir in onion and saute until tender, 3 to 4 minutes.

Whisk tomato sauce, 1/2 cup beef broth, flour, cider vinegar, Worcestershire sauce, Sriracha, sugar, chili powder, and salt together in a small bowl. Add to the onions and cook, stirring constantly, until mixture starts to thicken, about 2 minutes.

Stir in kidney beans and franks. Reduce heat to low, cover, and simmer until franks are heated through, 8 to 10 minutes, adding more beef broth if it becomes too thick.