Set oven to 400F.
Cook quinoa according to instructions given and set aside.
Slice off the top part of each tomato (and feel free to reserve the tops as garnish). Scoop out the pulp and set it aside in a bowl.
Set a nonstick skillet on medium high heat and add olive and garlic. Once the garlic cooks for about 2 minutes and slightly browns, toss in the onion and bell pepper. Cook for about 2 to 3 minutes.
Add the ground beef to the skillet and chop and cook using a wooden spatula to get the meat as fine as possible. As the meat cooks, add the seasonings. When the meat is nearly 85% finished cooking, about 6 to 8 minutes, toss in the cooked quinoa, tomato pulp, tomato sauce and fresh basil.
Reduce the heat of the skillet and mix everything to together for about 2 to 3 minutes, then remove from the heat.
Set the hollowed-out tomatoes into a baking dish, then stuff each tomato with the mixture and top each one off with shredded parmesan cheese.
Bake in the oven for 20 minutes.
Season to taste with sea salt & pepper.