Stir together the ingredients for the sauce in a small bowl or measuring cup until everything is well-combined.
Heat the avocado oil in a large skillet over medium-high heat. Once the skillet is hot, add the sliced onion and cook for 2 to 3 minutes, or until the sides of the onion begin showing some color.
Scoot the onion off to the side and place the ground beef in the center of the skillet. Allow it to brown for 2 minutes before breaking it up into smaller pieces using a spatula or wooden spoon.
Stir in the bell pepper, garlic, and jalapenos until well-incorporated and the garlic is fragrant, about 1 to 2 minutes.
Pour the sauce into the skillet and stir well. Bring everything to a full boil and cook, stirring occasionally, until the sauce has thickened and the vegetables have reached your desired level of doneness, about 2 to 3 minutes.
Stir in the fresh basil.
Serve the Thai Basil Ground Beef over steamed white rice, jasmine rice, brown rice, rice noodles, stir fry noodles, or cauliflower rice for a low carb option.