Preheat the oven to 180 degrees Celsius.
Start by cutting your beef into bite size pieces (or shred it, if you slow cooked it). Cut your carrots into 1cm chunks.
Put a large saucepan on a medium heat. Add the lardons and cook for two minutes until the fat begins to seep out.
Add the beef and carrots - stir.
Tip in the red wine and let it simmer down, then add the gravy. Turn down the heat and let it simmer while you cook the potatoes.
Peel your potatoes and cut into large chunks. Add to a large saucepan and cover with cold water. Put in a medium heat, bring to the boil then simmer for 20-25 minutes until the potatoes are soft. Drain.
Tip the drained potatoes back into the saucepan and add the butter along with a pinch of salt and pepper. Mash until smooth.
To finish the filling, get a small cup and mix the cornflour with 50ml cold water. Stir until smooth then tip into the beef sauce and stir until thickened. Add the frozen peas and stir.
Tip the beef mix into a large, high sided ovenproof dish. Top with the mashed potato and use a fork to smooth the top. Scatter the cheese on top and put in the oven for 40 minutes until golden.