Best 7 Layer Dip - Once Upon a Chef

Ingredients

• 2 cups cored, (seeded, and finely chopped tomatoes, from 2 to 3 large tomatoes (or 4 to 6 plum tomatoes))
• 1 bunch scallions, (thinly sliced, light and dark green parts separated (divided))
• 1 jalapeño pepper, (seeded and finely diced (divided))
• 4 tablespoons lime juice, (from 2 limes (divided))
• Salt
• ½ teaspoon sugar
• 3 tablespoons extra-virgin olive oil
• 3 cloves garlic, (minced (divided))
• 1 (15-oz) can black beans, drained and rinsed
• 1 teaspoon ground cumin, (divided)
• 2 tablespoons water
• 3 medium avocados, (halved, pitted and diced)
• 1 (8-oz) block sharp Cheddar, shredded (see note)
• 1 (8-oz) container sour cream (1 cup)
• 1¼ cups fresh cooked or canned (and drained corn kernels)
• Tortilla chips, (for serving)