Classic Guacamole (+ pro tip so it lasts longer)

Name: Classic Guacamole (+ pro tip so it lasts longer)
Prep time: 10 min
Total time: 10 min
Cuisine: Mexican
Ingredients: 3 medium avocados; 1/2 white onion (finely diced (about 1/3 cup)); 2 organic medium tomatoes (seeded and diced); 1/4 cup fresh cilantro (finely chopped); 2 garlic cloves (minced); 1 1/2 tablespoons fresh lime juice (roughly 1 lime); 1 tablespoon fresh lemon juice (roughly 1/2 lemon); 1/4 to 1/2 teaspoon ground sea salt; 1/2 teaspoon ground cumin; 1/8 teaspoon freshly ground black pepper; dash of crushed red pepper and/or cayenne pepper (optional)