Turkey Tostadas

Bahan-bahan (6 porsi)

• 1 tablespoon vegetable or canola oil
• ½ large onion, (chopped)
• 3 medium garlic cloves, (chopped)
• 20 ounces (1¼ pounds) lean ground turkey
• 1 tablespoon chili powder
• 2 teaspoons ground cumin
• 1 teaspoon ground coriander
• One 6-ounce can tomato paste
• 1 cup water
• salt, (to taste)
• 6 medium flour tortillas ((use corn, if gluten-free))
• One and a half 15-ounce cans refried beans, (warmed-up)
• 1 medium head iceberg lettuce, (chopped)
• ¾ cup shredded cheddar or cheddar/jack cheese
• ¾ cup grape or cherry tomatoes, (halved)
• ½ cup sliced black olives
• guacamole, sour cream, and salsa, for serving ((as desired))