Place the oil into a large skillet and heat over medium high heat. Add the diced onion and cook 3-4 minutes until softened. Add the garlic, oregano and red pepper flakes and cook 1 minute longer until fragrant. Add the tomatoes and their juices, tomato sauce, broth (or ouzo), salt, pepper and stevia if using.

Bring to a boil then reduce heat to a simmer. Simmer uncovered for 8-10 minutes or until the sauce is thickened. Taste and adjust seasoning to your liking.

Add the shrimp to the skillet. Cook 5-6 minutes until shrimp are cooked through and turn pink, stirring occasionally. Remove from heat and sprinkle with crumbled feta cheese. Cover the skillet and allow the feta to melt. Remove the cover and garnish with fresh parsley. Serve warm.