Prepare watermelon vinaigrette:
- In saucepan, combine watermelon juice and honey; cook over medium-high heat until reduced to about 3 cups.
- Stir in vinegar, shallots and mustard until blended.
- Gradually whisk in olive oil and vegetable oil.
- Season with salt and pepper; add mint sachet.
- Set vinaigrette aside.
- Season halibut fillets with salt and pepper.
- Coat bottom of large sauté pan with lemon olive oil; place over medium-high heat.
- Add halibut and sear on both sides, forming a golden-brown crust.
- Cook fish until it flakes with a fork but is still firm.
- Layer a slice of tomato on each of six plates; top with a slice of watermelon.
- Place halibut on top and drizzle with 1-2 ounces Watermelon Vinaigrette.
- Garnish with 1 asparagus spear, 1 tablespoon peas and 1 tablespoon cubed watermelon.