Μπιφτέκια με πατάτες στο φούρνο

500 g minced pork
500 g ground beef
1 onion
1 teaspoon tomato paste
2 cloves garlic
2 tablespoons vinegar
2 tablespoons olive oil
1 teaspoon paprika
1 teaspoon cumin
1/2 teaspoon curry
1 cup parsley
1 teaspoon vegetable salt
1/2 teaspoon pepper
1/3 cup milk
3 tablespoons Breadcrumbs
1 glass of grated halloumi

for potatoes:

1000 g potatoes peeled and cut into four
1/4 cup olive oil
1/2 teaspoon curry
1 teaspoon cumin
1 teaspoon vegetable salt
1/2 teaspoon pepper