Put a pot of water on to boil.

Heat oil in a large, high-sided skillet or Dutch oven over medium heat. Add onion, carrot and celery; cook, covered, stirring occasionally, until softened, about 10 minutes. Add garlic and cook, stirring, for 1 minute more. Stir in paprika, coriander, salt, pepper, cumin and cinnamon. Cook, stirring, until the vegetables are well coated and the spices are fragrant, about 45 seconds.

Increase the heat to medium-high and add bison. Cook, stirring and breaking it up with a wooden spoon, until no longer pink, 4 to 6 minutes. Add pomegranate juice and scrape up any browned bits. Stir in tomatoes and juice, 3/4 cup cilantro, mint and lemon juice. Bring to a simmer. Reduce heat; cook, uncovered, maintaining a gentle simmer and stirring occasionally, for 15 minutes. Add a little water if the sauce gets too thick; if it's too thin, increase the heat and boil for a few minutes. Season with more pepper and lemon juice, if desired.

Meanwhile, cook pasta in boiling water until just tender, about 9 minutes or according to package directions. Drain and divide the pasta among 8 shallow bowls. Spoon the sauce over the noodles and garnish with a dollop of yogurt and a sprinkle of the remaining cilantro.

Note: Greek-style yogurt is made by removing the whey from cultured milk, which gives the yogurt an extra-thick and creamy texture. Look for it with other yogurt in large supermarkets.

MAKE AHEAD TIP: Cover and refrigerate the sauce (Steps 2-3) for up to 3 days. Reheat on low; thin the sauce with a little water if desired.