In a small saucepan place the white wine and bring it to a boil. Add the saffron and stir it in so that it is dissolved. Remove the pan from the heat and let it cool. Add the Pernod and stir it in. In a medium bowl pour the wine mixture. Add the mahi mahi and coat it with the sauce. Let the fish marinate for 2 hours. In a small skillet place the olive oil and heat it on medium high until it is hot. Add the julienned fennel, thyme, tomatoes, salt, and pepper. Saut� the ingredients for 2 to 3 minutes, or until the fennel is tender. Set the mixture aside and keep it warm. In a large saucepan place the vegetable oil and heat it on high until it is hot. Add the reserved fennel stems and deep-fry them for 1 to 2 minutes, or until they are crisp. Drain them on paper towels, set them aside, and keep them warm. Grill the mahi mahi for 3 to 4 minutes on each side, or until it is just done. In the center of each individual serving plate place a fish fillet. Place the saut�ed fennel mixture next to the fish. Spoon the Garlic Mayonnaise between the fish and the fennel mixture. Place the deep-fried fennel on top of the fish for a garnish. For Garlic Mayonnaise: In a small bowl place the garlic, egg yolk, mustard, salt, and pepper. Whisk the ingredients together so that they are well blended. While whisking constantly, slowly add the olive oil so that a mayonnaise consistency is achieved. Add the boiling water to the mayonnaise, and stir it in well. Strain the garlic mayonnaise and keep it warm until it is served.