Bring a medium sauce pot of lightly salted water to a boil. Add the couscous and cook until tender, 4 to 6 minutes. Drain the couscous and return to the pot; fluff with a fork, cover, and keep warm.
While the couscous cooks, prepare the turkey keema.

• Peel and thinly slice the shallots.
• Finely chop, press, or grate enough garlic to measure 1 teaspoon.
• Cut a small corner from the ground turkey packaging and drain off any excess liquid. Transfer to a plate; pat dry with a paper towel.

In a large frying pan over medium heat, warm 2 tablespoons oil until hot but not smoking. Add the shallots and garlic, season with salt, and cook, stirring occasionally, until starting to soften, 2 to 3 minutes. Add the turkey and keema spice blend, season with salt and pepper, and cook, stirring to break up the meat, until lightly browned but not yet cooked through, 3 to 4 minutes.
Add the tomatoes and ½ cup water and cook, stirring occasionally, until the turkey is cooked through and the sauce is thickened, 3 to 5 minutes. Stir in the peas and cook until heated through, about 1 minute.
While the keema cooks, prepare the cucumber raita.

• Peel the cucumber, if desired, and trim the ends; thinly slice the cucumber crosswise.
• Strip the mint leaves from the stems; if desired, set aside several leaves for garnish. Coarsely chop the remaining leaves.
• Juice 1 lime.
• Cut the other lime into wedges for garnish.

In a small bowl, stir together the yogurt, cucumber, chopped mint, and lime juice. Season to taste with salt.

Transfer the turkey keema and couscous to individual plates. If using, garnish the keema and cucumber raita with the mint leaves. Serve with the raita and lime wedges on the side.