In a medium skillet on the stove top cook the sausage and onion together. Crumbling the sausage and cooking until it is no longer pink and the onions are translucent. Drain off excess fat from sausage.
Line a 6 quart or larger slow cooker with a Crock-Pot liners and spray with non-stick cooking spray (or just spray the crock-pot with non-stick cooking spray).
Pour approximately half of the tater tots into the bottom of the crock and half of the cooked sausage and yellow onions.
The next layer is half of the mozzarella cheese and half of the parmesan cheese.
Sprinkle tomatoes and green onions on top of the cheese (if you want to sneak in more veggies this is where you would put them).
Now you will repeat the layers. Tater tots and sausage with yellow onions.
The rest of both kinds of cheese is the next layer.
Then add the chopped tomatoes and green onions.
Now in a mixing bowl beat the eggs and milk with a whisk. Once it is smooth add the spices and stir a few times.
Pour over the top of the tater tot mixture, getting as much covered as possible. Cook on low for 8 hours or high for 4 hours.
If the eggs cook quicker you can eat it then. I scooped out a bit of the egg to judge if it was ready, as it was hard to just eyeball it.