4 tablespoons extra-virgin olive oil
divided
3 ½ teaspoons kosher salt
divided
2 teaspoons ground cinnamon
2 teaspoons ground cumin
2 teaspoons sweet paprika
1 teaspoon ground coriander
½ teaspoon ground black pepper
1 ½ pounds skinless
boneless chicken thighs
trimmed and cut into 1 1/2-inch pieces
1 large yellow onion
thinly sliced lengthwise
4 cloves garlic
smashed
4 teaspoons finely grated fresh ginger
2 ½ cups water
2 cups peeled and cubed (3/4-inch) butternut squash
1 (14.5 ounce) can diced tomatoes in juice
1 (5 ounce) package baby spinach leaves
3 tablespoons lemon juice
2 teaspoons lemon zest
salt and ground black pepper to taste