Cumin Lime Ground Beef Tostadas

Ingredients

• 1.5 lb. Ground Beef

• 3 tsp. vegetable oil

• ½ onion, diced

• ¼ tsp. garlic powder 

• 2 tsp. chili powder

• 1 tsp. cumin

• 2 tsp. salt

• 1 tsp. black pepper

• ¼ cup fresh lime juice

• 12 tostada shells

• refried beans, warmed through

Optional toppings

• crumbled queso fresco

• salsa 

• lime wedges