01 -
Season chicken with 1 teaspoon salt and 1/4 teaspoon black pepper. Heat a medium (10") heavy skillet over medium-high heat. Pour in oil and arrange chicken in skillet. Cook, turning halfway through, until golden, about 3 minutes per side. Transfer chicken to a plate.
02 -
Reduce heat to low. Cook garlic, tomato paste, and red pepper flakes, stirring, until garlic is light golden and fragrant and tomato paste has slightly toasted, about 30 seconds. Add broth, pumpkin puree, Parmesan, cream, lemon juice, and 1/2 teaspoon salt and whisk to combine. Nestle chicken back into skillet. Increase heat to medium and bring to a simmer. Cover and cook for 5 minutes.
03 -
Remove cover and continue to cook, stirring occasionally, until chicken is cooked through and sauce has thickened, about 5 minutes. Stir half of basil into skillet; season with salt and pepper. Sprinkle with remaining basil, shaved Parmesan, and red pepper flakes.