About 4 hours before smoking, mix together the syrup, garlic, pepper and chili flakes. Place the salmon on a sheet pan and coat with half the mixture. Refrigerate for about 3 1/2 hours. About 20 minutes before smoking, set salmon at room temperature. Set your smoker to 200F and add the birch. Once it's up to temperature, place the salmon on the wire rack in the middle of the smoker and barely crack the vent. You want it smothered in smoke. Every half hour, liberally brush the salmon with more of the syrup mixture. After 2 hours, check the salmon. Depending on the thickness of the meat, it should be cooked through and flaky. If it's not, continue to smoke until it is. It shouldn't take long. No need to worry about extra birch at this point, unless you want to add more. Discard the remaining syrup mixture. Serve hot or cold. Yield: 6-8 portions, depending on fillet size