In saute pan heat some olive oil and cook the mushrooms, baby spinach, and onions just until softened. Set aside to cool slightly.
In large bowl, combine the garlic, cheese, oregano, marinated artichoke hearts (leave undrained and chop the artichoke hearts to bite size), red pepper flakes and cooled mushroom mixture. Toss well but carefully. Season with salt and pepper to taste.
Arrange the flour tortillas on a large parchment-lined baking sheet. Divide the mixture evenly among the tortillas. Lightly drizzle with olive oil.
BROIL for about 2 minutes; only until the cheese has melted.