Heat a large skillet over medium heat. Add 4 tablespoons of butter and shallots to the skillet and cook for 3-4 minutes until translucent. During this stage it is important that you do not brown the shallots. Add the livers, thyme, and Madeira to the skillet and bring to a simmer. Cook, stirring constantly, for about 5 minutes or until the livers are beginning to brown but still tender and pink on the inside. Transfer the mixture from the pan into a food processor.
Add the cream and remaining butter, blending until very smooth. Transfer the paté into a jar or jars. Poke into the jar with the tip of a knife to help release any air bubbles and gently tap the jar on the counter.
Once any air bubbles are removed, smooth the top of the paté with the back of a spoon. Place plastic wrap directly onto the paté and place into the fridge to set for at least 4 hours or overnight.
Serve on a platter with blueberry mostarda, crostini and radishes for a decadent treat.
FOR THE MOSTARDA:
Add all ingredients to a small saucepan and bring to a simmer over medium heat. Cover and cook for 20 minutes.
Allow to cool before transferring to a jar and refine rating overnight.