Coat a large nonstick skillet with cooking spray. Add potatoes to pan; lightly spray top of potatoes with cooking spray. Cook 8 minutes, turning frequently (don't let potatoes brown too much). Reduce heat to medium, and cook 20 minutes or until tender, stirring and turning frequently. Transfer potatoes to a bowl. Wipe pan with a paper towel.
Combine egg substitute, onion, dill, salt, pepper, and eggs in a large bowl. Stir in salmon. Add potato, and stir gently to combine.
Heat oil in pan over medium-high heat and add garlic. Add potato mixture; cook 1 minute, gently pressing down potatoes with spatula to slightly flatten mixture in pan. Reduce heat to medium-low; cook 15 minutes or until egg has completely set around edges and has just set in the center, gently shakin pan frequently. Sprinkle with cheese and put under broiler 2 minutes.
Let cool at least 10 minutes. Cut into wedges, and top with sour cream. 6-8 servings. (Adapted from Cooking Light)