Season 1 liver with salt and pepper, add extra-virgin olive oil to the rendered duck fat in the same pan and saute for about 1 minute on the first side and 30 seconds on the second. Remove from the pan and let rest for a bit. Before serving chop and add to the quinoa.
Place a medium pot over medium heat and add 2 ounces fat, 1 shallot, and garlic and sweat for about 2 minutes. Add the quinoa and toast, about 1 minute, stirring to ensure the quinoa is coated in fat. Once toasted, add 2 cups seasoned chicken stock. Bring the mixture to a boil then reduce to a simmer for about 10 minutes, until the liquid is almost absorbed.
Add the reconstituted cherries, their liquid, toasted pine nuts, orange zest and orange juice to the quinoa and stir to combine. Add the freshly picked tarragon leaves and the chopped liver and toss to combine. Keep over the heat until all the liquid is absorbed.
For each serving, slice the duck breast on the bias and place next to a mound of quinoa. Drizzle the plate with extra-virgin olive oil. Place some of the dressed watercress on the plate and season with sea salt.