Total Time: 25 minutes
1. Combine egg yolk, lemon juice, vinegar, mustard, and salt in medium bowl. With a hand blender blend until sauce thickens. Add the almond oil in very slow thin stream, whisking constantly, until the sauce thickens. Add garlic, chili powder, and saffron and blend until sauce is smooth. If sauce gets too thick, add cold water as needed to achieve desired consistency. Cover and chill.
2. In a large saucepan melt 1 tablespoon butter and sauté leeks over medium-heat until translucent but not browned. Remove from pan and set aside.
3. In the same pan, heat the remaining butter medium-high heat. Season the halibut on both sides with salt and pepper and cook for about 3 minutes, until lightly browned. Flip fillets and cook about 4 minutes longer, until the fish is opaque in the center and browned on both sides.
4. To serve, divide leeks among 4 dinner plates, top with halibut and drizzle with aioli. Garnish with fresh chopped chives, serve.