Since opening Fat Salmon in 2010, chef Shawn Yoo has added unique sushi offerings to the extensive menu, flavors that go beyond spicy tuna and California rolls. Two that recently became permanent additions are the kimchi ya and the karaage papuru, inspired by flavors in Korean and in Japanese fast food.

Yoo wanted to incorporate kimchi, a Korean dish made from fermented cabbage, into a sushi roll. He rolled up yam tempura with cucumber and topped it with kimchi, sesame seeds, and scallions. The flavors come together in a tangy, slightly crunchy bite with acidity and some sweetness.

For the karaage papuru, he took Japanese-style fried chicken and combined it with scallion and spicy mayo, then topped it with purple (papuru in Japanese) cabbage to add a touch of freshness. The result is crunchy, salty, indulgent, and addictive.

"I wanted to add another flavor, and in Japan people serve it with white cabbage," he said. "But I didn't want to do that. Purple cabbage is more interesting."

Kimchi ya and karaage papuru rolls, $13 and $13.50 for an eight-piece roll; Fat Salmon, 719 Walnut St.; 215-928-8881;