Coat a nonstick skillet with olive oil cooking spray.
Saute onion, garlic, tomatoes and mushrooms for 5 minutes or until softened.
Add lemon juice and fresh dill.
Remove from heat.
Add salt and pepper to taste.
Spray a baking dish with olive oil spray.
Spread rice evenly over the bottom.
Top rice with salmon.
Cover each filet with vegetable mixture.
Cover pan with foil.
Bake for 20 minutes at 350°F(180°C).