Poached Salmon with Basil Butter and Succotash

Name: Poached Salmon with Basil Butter and Succotash
Ingredients: Kosher salt to taste; 1 cup mixed shell beans, such as cranberry, fava, lima, flageolets, and/or butter beans; 3 tablespoons unsalted butter, softened; 1 small onion, finely diced; 1 cup fresh corn kernels (from about 1 large ear of corn); 1 cup Chicken Stock, high-quality low-sodium store-bought chicken stock, or water; Black pepper from a mill; 1 large shallot, finely diced; Four 6-ounce wild salmon fillets, skin and any pin bones removed; 1/2 cup Fish Stock; 1/2 cup dry white wine; 1 teaspoon freshly squeezed lemon juice; 1/3 cup heavy cream; 1/2 cup (1 stick) cold unsalted butter, cut into 1/2-inch cubes; 3 tablespoons fresh basil (preferably a mix of green and purple basil) cut into chiffonade