This recipe can be made with virtually any sort of fish. Fish is a good choice for dogs and cats with skin sensitivities that flare up with more common meats like chicken or lamb.
Ingredients
4 fillets white fish such as cod or haddock
1 small sweet potato, cut into 1 inch cubes (use only half the quantity, cut into ¼ inch pieces, if serving to cats)
8 tbsp extra virgin olive oil (canola or other oil may be substituted)
2 heads fresh fennel, chopped, tough parts removed (use one head only and chop very finely if serving to cats)
(Optional for dogs) 2 cloves garlic, crushed or finely chopped

What to do

Preheat the oven to 350°F.
Place the sweet potato cubes in a pan of water and boil gently for about 12 minutes until tender.
Place the pieces of fish in a 1 inch deep baking pan.
Drain the sweet potatoes and carefully arrange the cubes around the fish.
Next, add the sliced fennel, scattering it evenly around the sweet potato and fish pieces.
Add the olive oil liberally and then sprinkle on the crushed garlic.
Place the pan in the oven and bake for 35 minutes.
Allow to cool sufficiently before serving.
Your pet’s portion may be served alone as an occasional meal replacement, or fed in small portions along with his usual fare.
Source: http://www.thehonestkitchen.com/recipes/healthy-fish-sweet-potato-bake/