Purslane and Avocado Tacos with Pico de Gallo

Name: Purslane and Avocado Tacos with Pico de Gallo
Ingredients: 1 pint grape tomatoes, quartered; 1/2 cup chopped white onion; 1 tablespoon lime juice, or to taste; 2 teaspoons minced fresh Serrano chile, or to taste; 1/4 cup chopped cilantro; Salt; Freshly ground pepper; 2 large garlic cloves, finely chopped; 1 tablespoon olive oil; 1 lb purslane, including tender upper stems, chopped (about 6 cups); 8 fresh corn tortillas; 2 avocados; 1/2 cup crumbled cotija cheese (about 3 ounces), or to taste; cilantro sprigs and lime wedges for serving