Drizzle the pumpkin cubes with lime juice, as well as the salmon cubes. Mix the sour cream, mustard, dill and a little lime juice. Peel and fillet the rest of the lime (including the white skin), chop the fillets as desired.
Peel the onions, cut eighths lengthways and fry them in a little olive oil in a pan that is not too small. Add the pumpkin cubes and thinly sliced garlic and cook for a few minutes. Salt and pepper.
Deglaze with Noilly Prat or white wine [if you like: add a little broth and let it boil down - depending on how soft you want the onions and pumpkin].
Add the salmon cubes and cook for a few minutes, stirring very carefully every now and then.
Pour sour cream sauce and lime fillets over the pan, mix carefully and season to taste.