Heat a 10-inch saucepan and when it's hot, add the butter. To the melted butter add garlic and red pepper flakes. Let this sizzle for 10-15 seconds.
Add in onions, tomato paste, oregano, salt, pepper, and water. Mix until you the tomato paste has dissolved. Cover the skillet and let the sauce cook for 3-4 minutes.
Remove lid and slowly stir in the heavy whipping cream, stirring all the while. Stir in shrimp, feta cheese, and olives and cook until the shrimp are cooked through, about 2-3 minutes. Garnish with parsley and serve.
You can use frozen, shelled shrimp for this recipe. Once you add the shrimp, just turn the heat to low, cover with a tight-fitting lid, and let the shrimp thaw on low heat.
The key to this dish is to not overcook the shrimp. As soon as you see them curl and turn pink, turn off the heat immediately. You're better off letting them cook in the residual heat, with the pan covered for 5 minutes, than you are overcooking them. No one wants rubbery shrimp!
If you plan to serve this later, add the feta cheese at the last minute to the heated shrimp. The cheese does melt and it makes it harder to reheat. The whole pieces of cheese also look wonderful in the finished dish.
For the non-keto members of the family, you can serve this over boiled pasta. You can use shirataki noodles or cauliflower rice for a low carb option. Depending on your carb allowance for the day, you might try my favorite lower carb (but not low enough for keto) noodles, Al Dente Carba-Nada Egg Fettuccine.
You can use queso fresco instead of feta. You just want some kind of salty, crumbly cheese for this recipe.
Use a colorful mix of olives to add even more visual appeal to this recipe. Chopped parsley at the end adds a great contrast to the colors in the recipe.