In a sauté pan, heat olive oil and add onions, thyme, mint & rosemary. Sauté onions until they have a nice golden color, about 5 minutes. Add the chicken broth and couscous. Stir well and bring to a boil. Once it reaches a boil, immediately turn it down to low and cover. Let it sit covered for 4-5 minutes until all of the liquid is absorbed and the couscous is tender. Add salt and pepper to taste as well as the lemon juice, toasted pine nuts, tomatoes, cucumber, dill and feta. Serve at room temperature or cold, and store leftovers in the refrigerator.