Heat butter and olive oil in a pot over medium heat. Add minced garlic and dates, and saute for about 4-5 mins. Remove ⅓ of the mixture from the pot and reserve for later.
Add the harissa, cumin, and cinnamon and cook down until the harissa darkens, about 2-3 minutes. Stir in the rinsed beans, broth, sugar, and a hefty pinch of salt. Bring to a boil, reduce to a simmer, and cook uncovered for 10 minutes.
While the beans cook, make your rice and the gremolata. To make the gremolata: Cut the mint into chiffonade (thin strips), chop parsley, and add pistachios. Toss in a bowl with zest of 1 lemon and a pinch of salt. Toss to coat.
Once beans have reduced slightly, add lemon juice and more salt to taste.
Serve over rice with the gremolata on top.
