In a large skillet pan set over medium-high heat on the stove-top cook the sirloin steak and onion together until the meat is brown and the onion is translucent. Drain off excess fat from the meat and set aside.
In a medium mixing bowl mix together the ricotta cheese, 1/2 cup of cheddar cheese, diced tomatoes, olives and jalapeños until combined and set aside.
Place one or more flour tortillas in the bottom of the slow cooker to cover the entire bottom of the slow cooker. Rip or cut tortillas to fit the bottom if necessary.
On top of the tortillas add layer of the ricotta cheese mixture.
Followed by a layer of beans, a layer of corn, a layer of meat, and then some shredded cheese.
Add another layer of tortillas, again covering entire surface and repeat the layers until you have used up all the ingredients making the last layer tortillas.
Be careful to only fill your slow cooker no more than 3/4 of the way full!
Add some salsa or picante sauce just to lightly coat the very top and sprinkle with a little more cheddar cheese if desired.
Cover and cook on LOW for 4 hours.
Cut carefully into serving sizes and top each serving with a little extra salsa if desired.
You don't have to be too worried about how you construct the layers, you can layer them as you see fit. Just use your tortillas at bottom and top to keep everything together as much as possible. Make sure to drain canned vegetables and meat or this will be too runny. The tortillas will be soft but you don't want them soggy. You can also mix this up and add other veggies or a different type of meat, or even do it without the meat.