Chicken Meatballs and Green Beans in Tomato Broth

Name: Chicken Meatballs and Green Beans in Tomato Broth
Ingredients: 1 lb. ground chicken, preferably dark meat; 4 scallions, finely chopped; 1 large egg; 2 Tbsp. red or white miso; 1 tsp. kosher salt; Freshly ground black pepper; 3 Tbsp. extra-virgin olive oil; 2 shallots or 1 small onion, thinly sliced; 4 garlic cloves, thinly sliced; 1 Tbsp. double-concentrated tomato paste; 1 pint cherry tomatoes; 12 oz. green beans or other pole beans, trimmed, sliced into 2–3 lengths; Kosher salt; Torn basil leaves (for serving; optional)