Heat oil in pan. Sauté garlic until fragrant, about 1 to 2 minutes. Add shrimp and fish cakes. Cook until shrimp turn pink and curl, about 2 minutes.
Add noodles, xiao bai chai, soy sauce, water, and fish sauce. Stir to get everything well mixed and until beehoon and xiao bai cai are cooked, about 5 minutes or so.
Remove and divide into 4 individual plates. Serve immediately.