Wash the thyme, pluck it. Mix with liverwurst, cream and cognac. Carefully spread with a teaspoon into the pies
Sprinkle thinly with sugar and caramelise with a gas burner (see below)
Perfectly caramelised
This is very easy with the small gas flambé burner. You can get it for example at Hagen Grote for 34,95 d + shipping costs. This is how it works without a burner: caramelise the sugar in a pan until golden brown and drizzle it immediately over the cream