Preheat oven to 350 degrees F and place rack in the middle position. Line 6 standard muffin wells with paper liners. Dice the strawberries. Zest the lemon. Mix the dry ingredients together.
Cream together the first five ingredients with a hand mixer until light and fluffy. Add 1 egg and cream again.
Add 1/3 of the dry ingredients beating well, followed by another egg. Repeat. Make sure to keep a light mousse-like texture through out mixing. Add the last of the dry ingredients, followed by the heavy cream. Fold in 1/2 of the strawberries and 1/2 of the chocolate chips. The batter will be very thick.
Spoon the batter into a zip-loc bag and cut a large hole in one of the corners. Squeeze the batter into each liner, mounding in the center. Alternately, use a muffin scoop. Sprinkle erythritol on the top of the muffins to prevent browning. Arrange the remaining strawberries and chocolate chips on top.
Place the muffin tin into the middle of the oven and turn the oven up to 400 for 6 minutes. Turn the oven back down to 350 and bake for 12-18 minutes more. The tops should be firm to the touch but still sound a little moist. Cool completely on a wire rack. Keep in the refrigerator and warm gently before enjoying. 4 net carbs each.