Heat 1 tsp oil in skillet over med; thinly slice onion + sauté 8-10 min until browned; season with salt + add 2 tbsp water; cover + cook 3-5 min until softened

Boil a large pot of salted water, add tortelloni + cook 4-6 min until al dente, then drain + return to pot

Reserve sauce from short rib packet; slice meat then add to the caramelized onion skillet with reserved sauce; heat over med-low 2-3 min, turning often, until warmed through

Divide tortelloni + meat to plates; drizzle each with caramelized onion sauce