In a large plastic zipper bag, combine flour, chili powder, garlic and salt.
Add catfish pieces and coat thoroughly.
Heat olive oil in a large skillet and brown catfish on all sides, about 3 minutes per side.
Remove fish to a plate and set aside.
Add onions to the skillet and cook for 5 minutes or until slightly golden.
Add beer, tomatoes with their juice, Worcestershire Sauce and Tabasco Sauce; simmer together about 10 minutes then return browned catfish to the skillet and simmer uncovered until done, about 15 to 20 minutes.