Coconut Curry Salmon

Ingredients

3 Scotch bonnet peppers, seeded, stemmed, and chopped (substitute habanero peppers if needed)
1/2 cup white balsamic (substitute apple cider vinegar if needed)
Pinch of kosher salt, plus more as needed
Pinch of granulated sugar
4 tablespoons vegetable or another neutral oil, divided
4 (6-ounce) fillets Coho salmon (such as Secret Island)
1 tablespoon unsalted butter
1 medium (9-ounce) yellow onion, finely chopped
4 garlic cloves, thinly sliced
3 tablespoons chopped fresh thyme leaves
1 green bell pepper, finely chopped
2 tablespoons tomato paste
3 tablespoons Madras curry powder
1 (13 1/2-ounce) can full fat coconut milk, well-shaken
10 ounces vegetable or chicken stock, or water
1 tablespoon fresh lemon juice, plus more as needed
5 green onions, thinly sliced, divided
6 cups cooked rice or coconut rice, for serving