Cut the beef into 1" cubes
In a small bowl, combine the flour with the smoked paprika, Mrs. Dash, chili powder, cumin and oregano and salt. Put this seasoning mix into a large resealable plastic bag with the beef cubes, and shake to coat the beef cubes.
Lightly spray a large nonstick skillet with nonstick spray and heat the olive oil over medium heat. Cook the onion and garlic for about 3 minutes, and then add the mixture with the flour and beef cubes. (If there's extra flour mixture in the bottom of the bag, set it aside)
Cook the beef for 8 to 10 minutes, until the meat is browned.
Stir in the canned Ro-Tel tomatoes with liquid, the beef or chicken broth, and any extra flour mixture. Crank up the heat to medium-high until the entire mixture comes to a boil, then turn the heat down to medium and let it simmer for about 30 minutes.
Preheat the oven to 350 °F
Spread some of the beef mixture on the bottom of an 8x8-inch casserole dish.
Lay 4 corn tortillas on top of the beef mixture, followed by half of the remaining beef mixture and 2 ounces of cheese.
Layer 4 corn tortillas on top, followed by the remaining beef mixture and 2 ounces of cheese.
Bake in the oven for 15 minutes until heated through.
Top with Greek yogurt, chopped tomatoes and salsa.