Peel and chop potatoes into equal-sized chunks.
Toss potatoes in cold water and bring to a boil until fork-tender.
In a bowl, whisk together flour, eggs, and milk until smooth.
Preheat your oven to 400°F (200°C).
In a large baking dish, place sausages and drizzle with oil.
Bake sausages until golden brown and sizzling—about 15 minutes.
Carefully remove the dish from the oven once sausages are browned.
Pour the batter over the sausages evenly.
Return it to the oven and bake for 25-30 minutes until golden brown on top and puffed up.
Slice into generous portions and serve hot with gravy or mustard on the side.