In a large skillet, melt 2 tbsp butter. season the livers with salt and pepper and add to the pan – cooking over high heat until browned. Transfer to a plate.
In same pan, melt 2 tbsp butter, red pepper flakes, garlic, shallot, thyme sprigs, and red onion. Stir until onions are soft, about 10 minutes. Discard thyme.
Add chicken broth and stir until slightly reduced and thickened. Add livers back into the pan and allow to simmer for about 5 minutes.
Remove from heat and cool for 10 minutes. In your food processor (mine is Cuisinart), puree livers and butter until smooth. Add cream slowly while processing until silky in texture.
Strain through a fine sieve or tamis into a bowl. This last step makes the mousse very light and smooth.
Chill in a bowl – then spread on french bread toasts and top with shallot jam or cherry cinnamon reduction.