Sheet Pan Cod with Vegetables in Lemon Herb Sauce

Name: Sheet Pan Cod with Vegetables in Lemon Herb Sauce
Ingredients: 1 lb. green beans (cleaned and trimmed); 1 yellow onion (thinly sliced); 8 cloves garlic (divided); 4 teaspoons avocado oil (divided); 2 teaspoons fine sea salt; 1-1/4 teaspoon ground black pepper; 1/2 cup parsley (cleaned and picked); 1/2 cup cilantro (cleaned and picked); 1/4 cup dill (cleaned); 1 scallion; 2 teaspoons lemon zest; 2 teaspoons lemon juice; 1 large zucchini (diced to 1/2 thick slices); 2 lb. wild caught cod (cut into 4 even pieces); lemon slices (for garnish)