Coriander Beef with Tortillas

Name: Coriander Beef with Tortillas
Ingredients: 3 cups water; 1 small onion, coarsely chopped; 6 fresh cilantro stems plus 1/4 cup coarsely chopped leaves; 1 garlic clove, smashed; 1 large jalapeño, thickly sliced; 1 tablespoon coriander seeds, crushed, plus 1 1/2 teaspoons whole seeds; 1/2 teaspoon whole black peppercorns; Salt; 1 pound skirt steak, cut crosswise into 2-inch-wide strips; 2 tablespoons fresh lime juice; 1/4 teaspoon freshly ground pepper; 1/4 cup plus 1 tablespoon vegetable oil; 6 large romaine lettuce leaves, shredded; 1 ripe Hass avocado, sliced; 3 medium radishes, sliced; 2 scallions, white and tender green, cut into 1/2 -inch pieces; Warm corn tortillas and hot sauce, for serving