Preparation Cook potatoes in large pot of boiling salted water until tender, about 10 minutes. Drain and return to pot; stir over medium heat until dry, about 1 minute. Add milk and butter; mash. Mix in mashed beans and green onions. Season with salt and pepper; cool 15 minutes. Place panko in large bowl. Drop 1/4 cupfuls potato mixture into panko; turn to coat. Coat bottom of 2 large nonstick skillets with oil; heat over medium heat. Divide potato cakes between skillets. Using spatula, flatten each potato cake to 2-inch round. Fry until golden, about 5 minutes per side.
Preparation Cook potatoes in large pot of boiling salted water until tender, about 10 minutes. Drain and return to pot; stir over medium heat until dry, about 1 minute. Add milk and butter; mash. Mix in mashed beans and green onions. Season with salt and pepper; cool 15 minutes. Place panko in large bowl. Drop 1/4 cupfuls potato mixture into panko; turn to coat. Coat bottom of 2 large nonstick skillets with oil; heat over medium heat. Divide potato cakes between skillets. Using spatula, flatten each potato cake to 2-inch round. Fry until golden, about 5 minutes per side.