Combine risotto, salmon and green onion, and mix well to combine. Scrape out onto a plate and divide into 6 equal mounds. Line a tray or baking sheet with plastic wrap. Use wet hands to shape risotto into cakes about 3⁄4 in (2 cm) thick. Lay on prepared tray, wrap in plastic and chill until firm – ideally overnight. (If your kids prefer two-bite cakes that they can pick up and eat with their fingers, it’s OK to make different sizes.)
Preheat oven to 300°F (150°C). Now create an assembly line: Measure flour onto a plate and season well with salt and pepper. Place eggs in a shallow bowl. Measure panko onto another plate. One at a time, dredge each risotto cake in seasoned flour, dip into beaten eggs, then coat with panko. Set aside and repeat until all risotto cakes are coated.
In a non-stick pan over medium low, heat 2 tbsp (30 mL) oil. Working in batches, fry risotto cakes 2 to 3 minutes per side or until golden. Place on a baking sheet in the oven to keep warm while you fry the rest, adding more oil to the pan as needed.
To make sauce, combine mayonnaise, yogurt, lemon juice, hot sauce and paprika in a bowl and whisk until uniformly combined. Serve with risotto cakes.