1For the meat roll, preheat oven to 220°C (approximately 425°F).
2Cook spinach in microwave and drain well.
3Season ground beef with salt and pepper and add thyme.
5Spread meat on a piece of wax paper and shape into a rectangle.
6Spread bacon slices on top.
7Place the cooked spinach on top of the bacon.
8Use wax paper to roll meat.
9Heat a little margarine in a skillet and add meat roll to pan.
10Sear meat on all sides and sprinkle with red wine.
11Place meat on a baking sheet and place small pieces of butter on top, or sprinkle with olive oil.
12Cut onions into quarters and arrange around the meat roll. Bake for 30 to 40 minutes in preheated oven.
13For the sauce, use cooked onions.
14Place onions in a saucepan with 200 ml wine and bring to a boil.
15Reduce heat and simmer for a few minutes. Season with salt and pepper and blend with an immersion blender.
16If necessary, pass through a sieve.
17For the mashed potatoes, peel potatoes and cut in quarters.
19Cook potatoes and leeks in plenty of boiling, salted water until knife-tender.
20Drain and grind to a puree in food processor or blender.
21Heat puree in a saucepan over low heat.
22Stir in warm milk, butter, mustard and season with a pinch of ground nutmeg.
23To serve, arrange meat and mashed potatoes and sauce on a plate.