Place the cucumber in a sieve and sprinkle with some sea salt. Let stand over a bowl or the sink for about 30 minutes. Meanwhile, prepare the rest of your ingredients. Once everything is chopped, place the bell pepper, jalapeño, green onions, maple syrup, olive oil, the lime zest and juice, and the avocados in a medium bowl. Mix well. Squeeze the water out of the cucumber with your hands and place in between two clean kitchen towel, removing as much water as possible. Add the cucumber to the bowl, along with the cilantro, and mix well. Place in the refrigerator for several hours, to allow the flavors to blend. Before serving, mix in the basil and season to taste with sea salt.