Caesar Salad with Grilled Steak

Name: Caesar Salad with Grilled Steak
Ingredients: ¼ cup mayonnaise; 2 tablespoons lemon juice; 2 tablespoons extra-virgin olive oil; 1 teaspoon Dijon mustard; 1 teaspoon anchovy paste; 1 small clove garlic, grated; ½ teaspoon ground pepper, divided; 2 tablespoons grated Parmesan cheese; 1 pound flank or sirloin steak (about 1 1/4 inches thick), trimmed; ¼ teaspoon salt plus a pinch, divided; 1 large tomato, chopped; ½ cup thinly sliced red onion; 1 large head romaine lettuce, cut lengthwise into quarters; Lemon wedges for serving