
Preheat oven to 375º.
Peel and chop sweet potatoes into 1” cubes and put in large bowl.
Add extra virgin olive oil, garam masala, garlic powder, onion powder, paprika, crushed red pepper, ground ginger, turmeric, chili powder, and salt to sweet potatoes and mix until sweet potatoes are coated.
Spread out in single layer on parchment paper lined baking sheets.
Bake for about 35 minutes until soft.
Roughly chop ginger.
Crush garlic cloves.
Add ginger, garlic, garam masala, paprika, cumin, crushed red pepper, chili powder, turmeric, salt to taste to food processor and blend.
Add olive oil as needed to make into a paste as blending.
Small dice onion.
Put tomatoes in food processor and blend until smooth.
Add 2 tbsp butter and 1/2 tbsp oil to large sauce pot over medium-low heat and let butter melt.
Add curry paste and stir to incorporate.
Let cook for 3-4 minutes until toasted and fragrant - stirring on and off.
Add pureed tomatoes and turn up to medium heat.
Stir and scrape bottom of pot.
Bring to a simmer then add heavy cream and roasted sweet potatoes.
Bring to a simmer and cook for about 10 minutes.
Add greek yogurt and lime juice and salt to taste.
Serve immediately with basmati rice, naan, chopped fresh cilantro and a lime wedge.