Shepherd's Cottage Pie

There are so many dishes that I've always wanted to try. At some point you read something about it, they are true classics and usually ends up with something else on the table. After all, I've done Szegediner goulash myself and I'll definitely repeat it.

And then there are the good old vegetables such. Salsify or turnips that have never landed in my pot. Kirsten of Sugar and Spice is doing it now and diligently using the good old vegetables. And that's what I have to imitate!
And one of the many dishes on my list of new chefs in the head is the "Shepherd's Pie" - a typically English classic, consisting of ground beef with vegetables, baked with a layer of potato-free.
I ate the Shepherd's Pie for the first time in the US. Even in the Cheesecake Factory, there is the Pie.
Since I totally rely on casseroles of any kind and absolutely wanted to try this potato crust, I tried today on a classic dish. Well, almost classic. I took a mix of lamb and ground beef, so it's not a real Shepherd's pie anymore. If beef is involved, Shepherd's Pie becomes Cottage Pie. But only lamb seemed too strict. That's why I'll just call it Shepherd's Cottage Pie.
Here's the recipe for 4 servings:
Shepherd's Cottage Pie
1 kg of floury potato
1 onion
1 clove of garlic
200 g of small carrots (about 6 pieces)
some sprigs of thyme
500 g lamb or ground beef or a mixture of both
150 g frozen peas
30 g butter
100 g of cheese, grated (Gouda, Cheddar or Parmesan to taste, for example)
100-200 ml of milk