Heat olive oil in a large skillet over medium heat.
Add in onion and saute until tender, about 4 - 5 minutes. Add garlic and sauté 30 seconds longer.
Pour in 1/2 can of diced tomatoes 1 tsp dried oregano and pepper flakes to taste.
Bring to a simmer then reduce heat to medium-low and continue to simmer, stirring occasionally, until sauce has thickened slightly, about 10-15 minutes. If it gets too thick add a little water so that you have a little runny sauce around the diced tomatoes.
Toss in shrimp and submerge in sauce. Cover and cook, tossing once halfway through, about 2 minutes each side.
Stir in the juice of half a lemon.
Sprinkle with feta and mint and allow to soak for a couple of minutes.
Salt to taste after you have added the feta cheese.
Serve warm with lemon wedges and cooked orzo or crusty bread. You can also serve it on a bed of rice or long pasta like wide Tagliatelle or Pappardelle.