Cut the salmon into cubes about 1 inch square.
In a large bowl mix together the thyme, zest of the lime and lemon and zest of 1 orange.
Add the olive oil to the bowl along with the juice from half of the lime, half of the lemon and juice from one orange.
Add the salmon to the liquid and toss making sure the salmon is well coated.
season with salt and pepper and let rest in the fridge for at least 1 hour.
Soak 6 wooden skewers in water to prevent them burning up on the grill too fast.
Once the salmon has marinaded, cut the other oranges into slices.
Place a piece of salmon on the skewer followed by a folded slice of orange and a chunk of red onion.
Follow this method until the skewer is full.
Repeat until all skewers are used. They don't have to all be exactly the same.
Preheat your grill to high and grill the salmon kebabs for about 3-4 minutes on one side and then carefully flip them over and grill for a further 3-4 minutes ending with nice charred grill marks for maximum flavor.
Serve at once with a salad or rice if preferred.