Make dipping sauce
Place the garlic, chiles, sugar and ginger in a mortar and pound into a paste. Transfer to a small mixing bowl and add the fish sauce and lime juice. Add cilantro. Set aside 15 minutes before serving.
Seed cucumber and cut into long, thin strips about the thickness of angel hair pasta. Add cucumber slices to Ginger-Lime Dipping Sauce and set aside.
Prepare fish
Heat vegetable oil in a large non-stick frying pan over high heat. Cook fillets until golden and just done, 2 to 3 minutes per side depending on the thickness. Halfway into the cooking, add whole garlic cloves and cook until soft. Remove fillets and garlic and drain on paper towels.
To serve
Arrange fillet on serving plate. Scatter cooked garlic cloves on top. Remove cucumbers from Dipping Sauce and neatly place on fillet. Drizzle some sauce over top and serve the remainder on the side.