In a large bowl, combine turkey, quinoa, garlic, beaten egg, olive oil, cheese, basil, oregano, salt and pepper. Mix thoroughly but quickly, just so the ingredients are combined – do not overmix! Roll into mini balls – slightly smaller than a golfball, and place on a baking sheet.
Layer sliced onion on the bottom of the crockpot and add 1 can of crushed tomatoes.
Heat a large skillet over medium-high heat (mine was actually almost high) and add 1/2 tablespoon olive oil. Add meatballs, searing on the top and bottom until golden, about 1 minute per side. To flip meatballs, gently toss with a spoon. I also shook the pan a few times to roll the meatballs around – if you pan is hot enough this works! Add meatballs one at a time to the crockpot. Repeat with remaining meatballs – it is okay to stack them once they are all finished.
Once all the meatballs are in the crockpot, add the other can of crushed tomatoes, completely submerging the meatballs. Cook on low for 6 hours. Serve!