Preheat the oven to 425°F and grease a 9x13 baking dish.
Mix the curry sauce: In the prepared baking dish, whisk together the coconut milk, red curry paste, cumin, salt, lime juice, garlic, and ginger until smooth and fully combined. Make sure the curry paste is well incorporated into the sauce. Taste and add more curry paste as needed. I did 3 Tablespoons without it becoming too spicy, but it's best to start with less and add more as needed.
2 (13oz) cans full-fat coconut milk, 2-3 tablespoons red curry paste, 1 teaspoon cumin, 1 teaspoon kosher salt, 1 Tablespoon lime juice, 4 cloves garlic, 1 1/2 teaspoons fresh grated ginger
Add the chicken and veggies: Add the chicken, onion, bell pepper, broccoli, and snap peas and stir to coat everything evenly in the sauce.
1 1/2 lbs boneless skinless chicken breast, 1 small yellow onion, 1 red bell pepper, 3 cups broccolini, 2 cups snap peas
Bake: Cover tightly with foil and bake for 20 minutes, until the chicken is mostly cooked through and the vegetables are starting to become tender.
Add noodles and bake again: Remove the dish from the oven and add the udon noodles, gently separating them as you mix them into the sauce. Mix the cornstarch with a few Tablespoons of water and stir into the sauce. Bake uncovered for another 10-15 minutes, until the noodles are al dente, the sauce is thick and creamy and the chicken is cooked through to 165°F.
8-10 oz udon noodles, 3 Tablespoons cornstarch
Taste and add more salt and lime juice as needed. Garnish with fresh cilantro, chili crunch or green onions.
Optional for serving: chopped cilantro, green onions, Thai basil, chili crisp, lime wedges