Heat oven to 375°F. Coat 9 x 2-inch round cake pan with nonstick cooking spray.
In large skillet, heat oil over medium-high heat. Add the onion, peppers and garlic; cook, stirring occasionally, for 7 to 8 minutes or until vegetables are softened; do not let garlic brown.
In large bowl, combine onion mixture, ground sirloin, half of drained diced tomatoes, the bread crumbs, yogurt, chiles, salt, chili powder, oregano and cumin. Spoon into prepared pan, spreading evenly. Spoon remaining drained diced tomatoes evenly over top.
Bake in 375°F oven for 55 minutes or until an instant-read meat thermometer inserted in the center registers 160°F. Let the meat loaf cool in pan 5 to 10 minutes. Carefully drain off any excess liquid from pan.
Slice into pie-shaped wedges.