Step 1Cut the leeks in half lengthwise and rinse out any dirt under cold running water. Pat them dry and drain on paper towels. Slice the leeks crosswise into 1/4-inch-thick slices. Set aside.
Step 2Spray a large nonstick skillet with cooking spray. Heat the skillet over medium heat, then add the oil. When hot, add the onions and cook until tender, about 5 minutes. Stir in the sliced leeks and cook, covered, stirring occasionally until tender, about 10 minutes.
Step 3Remove the stems from the dill and discard. Chop the dill, then stir it into the leeks during the last 5 minutes of cooking.
Step 4Add the chicken broth, rice, salt and pepper to taste. Bring to a boil, then reduce the heat to a simmer. Cover and cook until the rice is tender, about 15 minutes. Stir in the lemon juice.