3 pounds boneless beef chuck roast
3.5 tablespoons cornstarch, divided
0.5 teaspoon kosher salt
0.5 teaspoon ground black pepper
2 tablespoons canola oil
6 tablespoons Massaman curry paste
1 cup low-sodium beef broth
1 (13.5 ounce) can unsweetened coconut cream
1 pound baby Yukon Gold potatoes
2 tablespoons cold water
1 lime, zested and juiced
3 cups cooked jasmine rice
0.5 cup roasted cashews
1 cup chopped fresh cilantro leaves and stems
1 medium Fresno chile, thinly sliced
additional lime wedges, for serving, if desired