Joi's Cooking Pressure Cooker Coconut Curry Chicken

3 to 4 ripe tomatoes, halved through their equators
3 tablespoons ghee, unsalted butter or safflower oil
3 tablespoons virgin coconut oil
2 cups finely chopped onions
6 garlic cloves, grated on a Microplane or minced
2 tablespoons grated peeled fresh ginger
1 teaspoon cumin seeds
1 3-inch cinnamon stick or 1/2 teaspoon ground cinnamon
8 cardamom pods, lightly crushed with the flat side of a knife, or 1 teaspoon ground cardamom
2 teaspoons ground coriander
1 tablespoon kosher salt
1 teaspoon ground turmeric
¼ teaspoon crushed red pepper flakes
¼ teaspoon black pepper
2 ½ pounds boneless, skinless chicken thighs, cut into 1-inch chunks
1 to 2 teaspoons garam masala, to taste
½ cup canned unsweetened coconut milk
Cooked basmati rice, for serving (optional)
Plain yogurt, for serving (optional)
3 tablespoons finely chopped fresh cilantro, for garnish