Pre-heat the oven at 180 ºC / 350 ºF and prepare a baking tray to cook and cover it with baking paper.
In a large mixing bowl, mix ground beef with egg, onion and coriander powder, marinara sauce, chopped green & red bell pepper, onion, almond flour, and season with salt and pepper. Knead vigorously until reaching a firm consistency mix.
Use your hand and a spoon to shape into 16 balls. If it's sticky, you might want to grease your hand with some olive oil.
Cover each ball with a small piece of bacon on top or you can wrap bacon around the meat balls if you want. Place these meat balls in an orderly way on the baking tray and bake for 20 minutes until cooked.
Once the meat is cook, remove from the oven and while they are still hot, place a piece of cheddar cheese on top of each ball.
After that, place a piece of vegetable such as asparagus, red onion, red bell pepper and green bell pepper on each burger bite and secure with toothpicks. You can bake it again in the oven for 5 more minutes so the veggies can be cooked, or you can also serve it as it is. Enjoy!