1½ POUNDS BONELESS, SKINLESS CHICKEN BREAST
1 TEASPOON KOSHER SALT, PLUS MORE TO TASTE
2 TABLESPOONS UNSALTED BUTTER
2 TABLESPOONS EXTRA-VIRGIN OLIVE OIL
1 POUND SWEET ITALIAN SAUSAGE, (ABOUT 4 LINKS) EACH LINK CUT IN THIRDS CROSSWISE
4 CLOVES GARLIC, CRUSHED AND PEELED
2 MEDIUM ONIONS, CUT INTO 1-INCH WEDGES LEFT ATTACHED AT THE ROOT
¼ TEASPOON CRUSHED RED PEPPER FLAKES
1 SPRIG FRESH ROSEMARY
½ CUP APPLE CIDER VINEGAR
1 TABLESPOON HONEY
3 TABLESPOONS CHOPPED
FRESH ITALIAN PARSLEY
Slice the chicken breasts into ¾-inch strips on the bias, and season with ½ teaspoon of the salt. Add the butter and olive oil to a large nonstick skillet over medium-high heat. When the butter is melted, add the chicken and brown all over, about 2 to 3 minutes; remove it to a plate.
When all of the chicken is out of the skillet, add the sausage and garlic. Cook, turning the sausage, until it is browned all over, about 4 to 5 minutes.
Add the onions, and cook, turning the wedges, until they’re caramelized on the edges, about 8 minutes. Season with the remaining ½ teaspoon salt and the crushed red pepper.
Add back the chicken, tuck in the rosemary sprig, and pour in the vinegar and honey. Cover the skillet, and simmer until the onions have wilted and the chicken and sausage are cooked through, about 4 to 5 minutes.
Uncover, increase the heat, and boil until the sauce is reduced to a glaze, about 1 to 2 minutes. Stir in the parsley, season with salt if necessary, and serve.