Preheat oven to 425°F.
Wash carrots and allow to dry on towel.
Dice onion.
Sprinkle olive oil on bottom of roasting pan, add carrots, season with salt and pepper to taste, toss to coat carrots, and stir.
Roast for 20 minutes, stirring carrots every ten minutes. Add chopped onion, stir, roast another 10–20 minutes, or until carrots are cooked through with some blackened spots.
When carrots are fully cooked, remove pan from oven and allow to cool.
Add cool vegetables to food processor and process adding a bit of chicken stock, until smooth.
Place mixture in heavy-bottomed pan, add enough stock for the consistency and texture of soup you like.
Heat soup on low. (The soup will continue to thicken as it heats)
Add orange juice, grated orange rind, cayenne pepper, and grated ginger to taste.
Sprinkle parsley or marjoram on top of each serving.