Spicy Cabbage and Chorizo Soup

Name: Spicy Cabbage and Chorizo Soup
Ingredients: 2 tbsp. extra-virgin olive oil, plus more for drizzling; 1 large yellow onion, chopped; 8 oz. chorizo (approximately 2 1/2 links), sliced 1/4 inch thick; 4 cloves garlic, finely chopped; 1⁄4 tsp. red pepper flakes, or more to taste; 8 cups water; 1 lb. Yukon Gold potatoes, peeled and cut into 1-inch pieces; 1 small green or savoy cabbage (1 lb.), cored and thinly sliced; 1 (15-oz.) can navy or great northern beans; 2 tbsp. kosher salt, or more to taste; freshly ground black pepper; juice of half a lemon