Parmesan Rice Cakes

1 onion
3 tablespoons butter
1 cup rice
2 cups chicken stock
1/2 cup grated Parmesan cheese
1 slice whole wheat toast
3 eggs
Salt and pepper
2 tablespoons vegetable oil

Chop onion. In a large frying pan, melt 1 tablespoon butter over medium heat. Add onion and cook until softened, about 5 minutes. Stir in rice and cook 2 minutes. Add stock and bring to a boil. Cover, reduce heat and simmer until rice is tender, about 20 minutes; cool slightly. 

Meanwhile, grate cheese. Crumble toast and add to rice with eggs, cheese, 1/2 teaspoon salt and 1/4 teaspoon pepper. Shape the rice mixture into 8 patties. In a large frying pan, melt 1 tablespoon butter with 1 tablespoon oil over medium-high heat. Fry 4 patties, turning once, until golden brown, about 5 minutes. Remove from pan and keep warm. Melt the remaining 1 tablespoon butter with the remaining 1 tablespoon oil and fry the remaining patties.