In a medium frying pan, brown the ground beef, and add in the taco seasoning. Using a wooden spoon, start to combine until all the ground beef has been seasoned, then turn off the heat and set aside.
Slice off the top of the zucchini and slice them in half.
Using a small spoon, scoop out the flesh of the inside of the zucchini, leave just a little amount in the middle for the ground meat to go, so it forms a "boat"
To the zucchini boats, fill with two scoops of ground beef.
Top the ground beef with a spoonful of salsa.
Add a spoonful of black beans, then a sprinkling of Mexican cheese. Bake in the oven at 375º for 20-25 minutes or until the cheese melts.
For the Avocado Crema
Add all ingredients to a food processor or blender and blend until smooth.
Add any additional lime juice or salt as needed or desired.