Pre heat your oven to 375 degrees. Place the flour tortilla shell on a pizza pan. Microwave the cream cheese for 10 seconds to soften. Spread the softened cream cheese on the flour tortilla shell. Leave a 1/2 inch gap on the tortilla shell with no cream cheese at the edge. Add the minced smoked trout and chopped red onion on top of the cream cheese. Sprinkle the shredded mozzarella cheese on top of your pizza. Keep the edge of the tortilla shell free of the cheese. Bake at 375 degrees for 10-12 minutes, till the top is lightly browned and the tortilla shell is crisp. Serves two.