Kodok goreng mentega - indonesian "butter fried" frog legs

Ingredients

• about 0.5 lb frog legs
• 1 onion, sliced thinly
• 0.5 cm ginger, crushed
• 2 cloves garlic, crushed
• a sprig of spring onion, cut into long chunks
• olive oil, butter, light soy sauce, sweet soy sauce, Worcestershire sauce, pepper, a bit of corn starch, a bit of hot water