In a large frying pan, heat the olive oil and butter, then lay bread slices (if you can’t fit them all in at once, do it in two batches) in the pan. Let it cook for a couple minutes, just until it’s slightly golden, then flip with tongs and toast for another minute or so. (If you do this in two batches, you may need to add a bit more oil and butter to the pan before adding the second batch.)