In a food processor, blend together the canned chopped tomatoes, bell pepper, minced garlic clove, chili flakes, mustard, apple cider vinegar, coconut aminos and erythritol. Set aside.
Turn the “saute” mode on your instant pot and let it heat up. Pour in olive oil and wait until hot. Then add onion and remaining garlic and saute for 1 minute.
Add ground beef. Season with salt and pepper and cook while stirring occasionally for 6-7 minutes or until lightly browned. Crumble the beef with a spatula while cooking. Turn the “saute” mode off.
Stir in the sauce. Put the lid on and turn the valve to “sealing.” Press “pressure cook” (manual) and cook on high pressure for 15 minutes.
Once finished cooking, do a quick release. Take the lid off and give a good stir.
Divide between bowls, sprinkle with shredded cheddar and green onion (optional) and serve with some leafy greens.