Make Crepe Batter: In a bowl, whisk together flour, eggs, milk, and salt until smooth. Let rest for 10 minutes.
Cook Crepes: Heat a non-stick skillet over medium heat and brush with olive oil. Pour 1/4 cup of batter, swirling to form a thin layer. Cook for 1-2 minutes until edges lift, then flip and cook for 30 seconds. Repeat to make 10 crepes. Stack on a plate.
Sauté Aromatics: In the same skillet, add a drizzle of olive oil and sauté onion for 2-3 minutes until soft. Add garlic and mushrooms (if using) and cook for 1 minute until fragrant.
Brown Beef: Add ground beef, breaking it apart. Cook for 5-7 minutes until fully browned. Drain excess fat.
Season and Simmer: Stir in paprika, thyme, chili powder, salt, pepper, and tomato sauce. Simmer for 5 minutes to blend flavors. Add cheese if desired.
Fill Crepes: Spoon 2-3 tablespoons of filling onto the center of each crepe. Fold or roll to enclose the filling.
Serve: Arrange crepes on a plate, garnish with parsley, Greek yogurt, or hot sauce, and serve warm.