Cook rice according to rice cooker instructions, using a 1:1.5 rice-to-water ratio.
While rice is cooking, peel and devein shrimp (if needed), then rinse and pat dry. Season shrimp in a bowl with salt, pepper, cumin, coriander, and Aleppo pepper. Set aside.
Then, chop cilantro, green onions, garlic, and mint leaves. Set aside.
When there are about 10 minutes left on your rice, add 1 tbsp butter and 3 cloves garlic to a pan over medium low heat. Sauté garlic, stirring occasionally, until most of the pieces turn golden brown and garlic is fragrant.
Then, add shrimp to pan, keeping all shrimp within one layer (try not to stack them on top of each other). Cook shrimp until the edges start to turn pink, then flip over and cook on the other side until the shrimp is mostly opaque, about 3-4 minutes. Do not overcook the shrimp, otherwise they will become too chewy. Once the shrimp is cooked, remove from heat and set aside.
To make cilantro lime butter, add remaining 2 tbsp butter to the same pan that you cooked the shrimp. Once the butter is melted, turn off the heat. Add 1/2 cup cilantro, and using a microplane, zest one lime into the pan. Cut this same lime in half and squeeze the juice into the pan. Stir gently to combine.
Your rice should be ready by now; remove rice from rice cooker and place into a bowl. Squeeze juice from one lime over rice, then add remaining 1/2 cup of cilantro, along with the green onions, mint, and 1/2 tbsp of your cilantro lime butter. Drain black beans and add about a half of a can to the bowl with the rice. Gently fold rice mixture using slicing motions until well-combined.
Serve shrimp over rice and drizzle with remaining cilantro lime butter. Top with pickled onions, if desired.