Heat a safe nonstick skillet over medium-high heat. Add the ground beef and cook, stirring occasionally until cooked through. Drain.
Return to heat. Stir in the salt, garlic powder, chili powder, cumin powder and dried oregano. Heat over low heat.
Meanwhile, prepare the salads. Divide spinach among plates and top with onion, avocado, olives and jalapeños, leaving room in the center for the meat and salsa.
Scoop out the taco meat and place a mound in the center of each salad.