Make the chicken in a large bowl. Whisk the salt with 6 cups of cold water until dissolved. Add the chicken and refrigerate for 45 minute.

Remove the chicken and pat dry with paper towel. Wipe out the bowl. In the same bowl, whisk the olive oil with the garlic, rosemary, lemon zest and crushed red pepper. Add the chicken and turn to coat, rubbing some of the marinade under the skin. Marinate the chicken at room temperature for 45 minute.

In a large skillet heat the olive oil. Fry the chicken over moderate heat, turning occasionally, until lightly charred and an instant-read thermometer inserted in the thicket part of each leg register 165°, about 25 minute.

Meanwhile, make the fricassee in another large skillet, cook the scallion over high heat until charred on the bottom, about 3 minute. Transfer to a work surface and cut into 1-inch length. In the same skillet, heat the olive oil. Add the onion and a generous pinch of salt and cook over moderate/high heat, stirring occasionally, until softened and lightly browned, about 6 minute. Add the sausage and cook, breaking up the meat with a wooden spoon, until nearly cooked through, 6 to 8 minute. Add the corn and tomatoes and cook, stirring occasionally, until the corn is crisp-tender and the tomatoes are softened, about 5 minute. Stir in the snap peas and cook until crisp-tender, about 2 minute longer. Stir in the basil and scallion and season with salt. Transfer the fricassee to a platter, top with the chicken and serve.