Heather's Cilantro, Black Bean, and Corn Salsa

INGREDIENTS

• 1 (15 ounce) can yellow corn, drained
• 1 (15 ounce) can white corn, drained
• 2 (15 ounce) cans black beans, drained and rinsed
• 1 (14.5 ounce) can Italian-style diced tomatoes, drained
• 1 bunch finely chopped cilantro
• 5 green onions, finely sliced
• 1 small red onion, finely chopped
• 1 red bell pepper, seeded and chopped
• 1 tablespoon minced garlic
• 1/4 cup lime juice
• 1 avocado - peeled, pitted, and diced
• 2 tablespoons olive oil, or to taste