Preheat oven to 425. Place mixed seeds in small skillet and toast over medium to low heat. Set aside to cool.
Cut carrots lengthwise and place in a large bowl. Add cumin, paprika, garlic, thyme, lemon and orange. Drizzle with 1/4 cup olive oil and red wine vinegar. Toss well to coat.
Place on heavy, oven-proof pan, and roast at until carrots begin to caramelize, but are still crunchy. Remove from the oven and let cool.
Squeeze lemon and orange juice into a bowl along with all pan juices. Slowly drizzle in remaining olive oil and whisk constantly until emulsified.
Slice avocado and squeeze lemon juice on top to prevent browning.
Return carrots to bowl, along with salad greens and red onion, and toss with dressing.
Place on serving platter or individual plates, arrange several pieces of avocado amongst carrots and greens, drizzle with crema and sprinkle with seeds.