Using vegetable peeler, shave carrots and cucumber lengthwise into ribbons. Cut ribbons into 3-inch-long sections, then cut sections into matchstick-size strips. Place in large bowl. Add shallots, jalapenos, lime juice, sugar, and fish sauce; let marinate 30 minutes at room temperature. Add trout pieces and tomatoes to vegetable mixture and toss to blend. Transfer trout-vegetable mixture to large strainer and drain off liquid. Return trout-vegetable mixture to same bowl; add mint and basil and toss to blend. Arrange lettuce leaves on large platter. Divide trout-vegetable salad among lettuce leaves. Drizzle sweet chili sauce over each salad and sprinkle with peanuts. * Available in the Asian foods section of most supermarkets, at some specialty foods stores, and at Asian markets. ** Available at some supermarkets and at specialty foods stores and delicatessens. ***Available at some supermarkets and at Asian markets and from amazon.com.