Sautee onions in a large saucepan or pot with olive oil until soft - on medium high heat. Once soft, add garlic and cook for 1-2 minutes until garlic is slightly brown.
Add in ginger, tomato paste, and broth. Stir until well combined. Add in the curry powder, garam masala, cumin, coriander, turmeric, cardamom, and salt.
Add in coconut milk, greek yogurt, and fresh lemon juice. Stir until mixed well, then add in sugar.
Simmer for 10 - 15 minutes then adjust sugar level as needed - add more if you'd like and if it's too sweet add a little extra coconut milk or yogurt.
10 minutes before you are ready to serve, add frozen bag of shrimp and heat until warmed through. Can let simmer until ready to eat.
Serve with basmati rice and naan. Top with a dollop of greek yogurt and some fresh cilantro. Enjoy this sweet and creamy curry!