In a large bowl combine the olive oil, balsamic vinegar, lemon juice, orange juice, mustard, salt, and pepper.
Slice or tear the green lettuce and frisée into bite sized pieces. Place them in the bowl with the fennel. Toss to combine. Add the pears and apricots and toss again.
Notes
The dressing can be made a couple of days ahead of time and stored in the refrigerator.