Slice the beef into 2.5cm/1 in cubes. Peel the onions and slice them in rings. Cut open the pepper, discard the seeds and stem, then chop the flesh up finely. Peel the garlic. Slice the bacon into small pieces. Top and tail the carrots and grate them finely.
Preheat the oven to 140°C/275°F/gas mark 1. Put 2 tablespoons of the olive oil into a large cast iron or other flameproof casserole over a fairly high heat. Add the beef and brown all over. Using a slotted spatula, transfer it to a plate on one side. Add the remaining oil to the casserole, then add the onions and fry until richly brown. Return the beef to the casserole. Add the whole garlic cloves, the red pepper, bacon, grated carrots and oregano. Pour in the wine and balsamic vinegar and stir to mix together, adding salt and black pepper. Cover the casserole and bring the mixture up to bubbling on top of the stove, then put it on a low shelf in the oven and cook for 3 hours. After this, slice the olives up roughly, add to the casserole and put back in the oven for another hour. Remove from the oven, add a little more salt and pepper if necessary, then spoon the mixture into a pie dish that it just about fills and leave until cool.
Preheat the oven to 200°C/400°F/gas mark 6. Meanwhile, make the pastry. Sift the flour, baking powder and salt into a bowl and stir in the breadcrumbs, cheese and suet. Stir in enough cold water to make a stiff dough. On a floured surface, roll out the pastry into a piece slightly larger than the pie dish. Moisten the edges of the dish and lay the pastry on top, pressing the edges down lightly. Cut 2 holes in the pastry to allow steam to escape and then trim the edges. Roll out the trimmings and cut out decorations. Moisten the underside of these and arrange on the pastry. Brush the pastry with milk and bake the pie in the centre of the oven for 25-35 minutes, until golden brown.