Toss the potatoes with the oil and season with salt and pepper. Roast at 450 for 13 minutes until lightly browned on the bottom and corners but undercooked in the center. Remove from the oven and allow to cool.
Melt the butter in a frying pan and add the sausage, onion, carrot, and celery. Cook about 7 minutes to soften and break up the sausage. Add in the herbs and cook 2 minutes. Remove from heat.
Pulse the cooled potatoes in the food processor until you end up with the chunks being pea sized or smaller.
Mix the potatoes with the veggie/herb/butter mixture, the breadcrumbs, and the egg. Stir to combine.
Form tots with your hands.
Fry at 350 for about 5 minutes until browned.
Remove to a rack, salt, and serve with warm gravy.
* If you don't want to fry these, my favorite way to cook them is in the oven at 450 in a mini muffin tin. It forms coin shaped tots that get nicely browned and crunchy. Only put the filling up to a half inch inside each muffin spot.