Line a perforated pan with baking paper (a solid pan will do if you don’t have a perforated one, but it may take a minute or two longer to cook the bacon).
Lay the bacon out in the pan, making sure it’s single layer with no overlap. If you’re using diced bacon, just spread it out as best you can and make sure there isn’t too much bacon in there. In either case you’re better to use two sparsely covered pans than one over filled one.
Put the pan into a cold oven and set to 400°F/200°C, combination steam setting. If your oven has variable steam settings, use 50% (if not, don’t worry! Just set to combi or convection steam at the correct temperature and the oven will sort out the steam level for you).
Cook the bacon until it’s sizzling and golden, around 12-15 minutes for thick slices or 8-10 minutes for diced pieces. Go for the right color rather than a set time. It may not seem very crispy when you take it out of the oven, but will crisp up as it cools slightly.
Either use or serve the bacon immediately, or cool and store in a covered container in the fridge for up to 4 days. If I’m storing it, I like to drain the bacon on a paper towel for a minute or two before putting it away. Stored bacon can be reheated in a dry oven at around 300°F/150°C for a few minutes, just until it’s hot.