1/2 teaspoon fennel seeds
1/4 teaspoon coriander seeds
1 cup plain yogurt
1/2 cup lightly packed fresh mint leaves, finely chopped, plus 3/4 cup whole leaves
Kosher salt
1 cup frozen peas, thawed and drained
1 cup frozen edamame, thawed and drained (if you can't find these, or don't like them, substitute with an extra cup of peas)
1 large shallot, peeled and roughly chopped
1 clove garlic, peeled
2 tablespoons extra-virgin olive oil
Generous 1/4 cup chickpea flour (besan, available at Indian stores; regular flour is a fine substitute)
Canola oil, for frying
2 large pitas, halved
2 large vine-ripened tomatoes, cut into large dice
1 large English cucumber, sliced into 1/8-inch rounds