Place shrimp, juice of limes and orange, salt, garlic, green onions and 1/2 jalapeno seeded and chopped and 1/2 serrano pepper seeded and chopped in a bowl. Make sure that juice covers the shrimp completely. Stir well. Place in fridge for 20 minutes to marinate and cook the shrimp. If kept too long in the marinade, shrimp will over cook, and will tend to turn it chewy.
While shrimp is marinating, cut up the tomatoes into bite size pieces, chop 1/2 bunch cilantro, avocado cubes, and 1/2 cucumber chopped into bite sized cubes.
Take shrimp out of the fridge, and drain only the juice. At this point, you can choose to cut the shrimp up in half or leave them whole. Add shrimp along with marinated onions and peppers to the tomato mixture and toss. Enjoy with your favorite low carb tortilla, fried into a tortilla chip. Or use as a topping over fish or a salad.