Nutritious Grapefruit and Couscous Salad

For the salad: 

• ¾ cup (180ml) vegetable broth (stock)
• ¾ cup (130g) couscous, uncooked 
• 1 avocado, pitted and cubed 
• 2  grapefruits, peeled and segmented 
• 14 oz. (400g) can cannellini beans, drained and rinsed 
• ½ cup (75g) feta cheese, crumbled 
• 3 tbsp. fresh mint, chopped 
• 3 tbsp. fresh cilantro (coriander), chopped 

For the dressing: 

• 3 tbsp. lemon juice 
• 2 tbsp. grapefruit juice, preserved from segmentation 
• 1 tbsp. honey 
• 2 tbsp. olive oil 
• ¼ tsp. salt 
• ground black pepper, to taste