Lumpy custard? Don’t panic, this can happen if the eggs get too hot when the milk is added. Simply strain the custard through a fine sieve before adding the chocolate and cooling.
Alternatively, for a quick and easy option, grab a 500g tub Finest Cornish custard and gently heat through until just hot, but not bubbling. Remove from the heat and stir through the chopped chocolate as in step 2. Allow to cool completely, then layer up in the trifle as above.