Cajun Mac & Cheese Cakes

(adapted from a recipe by Colleen Hossack)
1 lb macaroni or other pasta, cooked
3 cups béchamel, freshly prepared
2 tbs butter
1/4 red onion, finely diced
1 small white onion, finely diced
1 1/2 cups fresh or frozen corn niblets
1 cup grated old cheddar
1 cup grated smoked gouda
2 tbs Cajun spice blend
kosher salt/fresh ground pepper to taste
2 eggs, beaten with 1 tbs water
2 cups bread crumbs
vegetable oil for pan-frying
Melt butter in a skillet over medium-high heat. Add onions and corn. Sautee until onions are translucent and corn is tender.
Stir cheeses and Cajun spice into warm béchamel. Season to taste, then fold in pasta, onions and corn. Adjust seasoning. Transfer pasta mixture into a large baking dish and refrigerate several hours until firm. Turn out of dish and cut into cubes. Dredge each in egg, then bread crumbs. Pan-fry, turning to cook until golden on each side.