Preheat the oven to 350ºF (175ºC). Position the oven racks to the upper third and lower third positions. Line 2 large sheet pans with parchment paper. Set them aside. 

In a small bowl, mix together all the ingredients for the tamarind glaze. Measure 2 tablespoons of the tamarind glaze and set that aside. You will need it after you finish roasting the tempeh and vegetables.

Add the tempeh, sweet potatoes and pepper into a large bowl. Toss them with the tamarind glaze that's remaining in the small bowl. Spread the tempeh and vegetables over a sheet pan.

Pat the chickpeas with a paper towel to absorb some moisture. In a bowl, toss the chickpeas with a tablespoon of olive oil and 1/4 teaspoon of salt. Spread the chickpeas over the other sheet pan.

Place the sheet pan with the tempeh on the upper rack in the oven and the pan with the chickpeas on the lower rack.

Bake for 30 minutes. Give the tempeh, vegetables and chickpeas a quick stir. Bake for another 10 to 15 minutes, until the sweet potatoes are tender and the tempeh is golden brown. Turn off the heat. Remove the sheet pan with the tempeh and vegetables from the oven. Leave the chickpeas inside so that the residual heat from the oven continues to roast them. 

Sprinkle the lemon zest on top of the tempeh and vegetables. Pour the reserved tamarind glaze over everything and stir to combine. Sprinkle with chopped parsley and feta.

Remove the chickpeas from the oven. Serve the tempeh and vegetables with the roasted chickpeas.