Loaded Taco Salad

Name: Loaded Taco Salad
Ingredients: 3 tbsp. canola oil; 1 lb. ground chuck; 1 package Taco Seasoning; 2 scallions; 1 c. fresh or canned corn; 1 carrot; 1 c. coarsely chopped cilantro; 1 can black beans; 1/2 c. grated sharp Cheddar cheese; 1/2 c. grated Monterey Jack cheese; 1 ripe avocado; 1 head lettuce (or equivalent amount of mixed greens, such as arugula or baby romaine); 1/2 c. extra-virgin olive oil; 2 tbsp. lime juice; 1 tbsp. rice wine vinegar; 1 tbsp. red wine vinegar; 1/2 tsp. onion powder; 1/2 tsp. kosher salt; Some cracked black pepper