Bring a medium saucepan of salted water to the boil. Peel potato and cut into large chunks. Cook in the boiling water until easily pierced with a knife, 12-15 minutes. Drain and return to pan. Add the butter, milk and the salt. Mash until smooth.

While potato is cooking, finely chop onion (see ingredients) and carrot. Pick and finely chop herbs. Finely chop garlic. Roughly chop mixed leaves.

In a large frying pan, heat a drizzle of olive oil over high heat. Cook onion and carrot, stirring, until softened, 6-7 minutes. Add garlic (reserve a pinch for the beans!), chopped herbs and Italian herbs (see ingredients) and cook, stirring, until fragrant, 1 minute. Add beef mince and cook, breaking up with a spoon, until just browned, 3-4 minutes. Reduce heat to medium, then add tomato paste, the water and beef stock pot, stirring to combine. Add baby spinach and cook, stirring, until just wilted, 1-2 minutes. TIP: Add a dash of water if the filling looks dry!

Preheat grill to medium-high. Transfer the mince filling to a baking dish. Spread the mash over the top potato over the top. Sprinkle with grated Parmesan cheese. Grill until cheese is melted and golden, 5-10 minutes. TIP: Grills cook fast, so keep an eye on the pie!

While pie is grilling, trim the green beans. Wash out and dry frying pan, then return to medium-high heat with a drizzle of olive oil. Cook beans, tossing, until tender, 3-4 minutes. Add reserved garlic and cook until fragrant, 1 minute. Season with salt and pepper.

Divide herby beef cottage pie between plates. Serve with green beans.