Melt butter in a deep skillet over medium-high heat. Saute onions in hot butter until soft, about 5 minutes.
Pour 1 cup water in the skillet and bring to a simmer. Lay fillets into the water and poach until fish flesh can be gently broken with a fork, 5 to 7 minutes. Remove fish and onions from the skillet with a slotted spoon to a bowl.
Pour remaining 1/4 cup water into the skillet with the potato cubes; season with salt. Place a cover on the skillet and bring the liquid to a boil; cook until the potatoes are beginning to soften, but remain firm, 5 to 7 minutes.
Return fish and onion to the skillet; add whole milk and evaporated milk. Season everything with salt and pepper; heat until just before the liquid comes to a boil and remove immediately from heat.
recipepes.comMom's Fish Chowder, recipePT15MPT1H5455 calories