Drain the can of salmon, break the fish into large flakes, set aside. Remove the avocado stones. Slice lengthwise from the rounded end. Do not slice completely through the narrow end. Slice each half into 5 pieces, put on a serving plate and spread the slices out fan-like. Brush with lime juice. Arrange the endive on the plates and place the salmon flakes on top. Mix together the cucumber, mint and yogurt. Pour onto the salad. Serve at once. Serves 4. Approx. 300 kcals per serving