Heat mashed potatoes according to package directions.
Cook garlic in butter on low heat for 1-2 minutes just until they release their oil. Add garlic and butter to a pot with chicken broth, taco seasoning, cumin, garlic, & the rest of the butter. Heat to boiling. Add shrimp & heat through.
Spoon a mound of mashed potatoes high into the center of a soup bowl. Fill surrounding area with shrimp and broth. Serve with crusty french bread.